That was until Grahlmann was gunned down at his home in California just over a year ago, leaving a fortune. The former Mrs Grahlmann is now worth pounds 12.5m. Unfortunately there is a hitch in this extraordinary turn of events. Not only is the heiress's identity unknown, but so too are her whereabouts. She may not live in London at all. She may be dead. She may not even exist.
The mystery woman, of whom almost nothing is known but her stocking- drying habits, has become the focus of a transatlantic hunt.
The latest part of this bizarre story starts in the late afternoon of 23 October 1998 in the hills overlooking the pretty resort town of Guerneville, 60 miles north of San Francisco. Horst "Hans" Grahlmann, a 57-year-old millionaire, was sitting on a bench outside his secluded cabin admiring the view while his employee and friend Jason Blore, 26, fixed the roof. An unknown gunman shot Grahlmann dead with a single shot to the head. Blore's body was found inside the building. He had been shot 11 times with a semi-automatic AK47 Russian rifle. Police believe the killer had a grudge against the younger man, and that his boss had just got in the way.
The murder caused a sensation in the small community of Guerneville where Grahlmann was well known for his wealth and his eccentric, occasionally exhibitionist behaviour (one of his party tricks was to unzip his flies and flop the contents on to the bar). Although he was known to have millions of dollars invested in real estate, he was famously reluctant to spend any of it.
"He could be very frugal," said one friend. He always ate at home, driving miles in his old VW van to get the best shopping bargains. He owned a fleet of classic cars, with several valuable Mercedes, but kept them under wraps as an investment. Every Sunday he could be found at the local flea market and a business partner has said that if a stranger saw him in the street, he might be tempted to offer him a dime: "You would expect him to stick his hand out - he looked like a panhandler, real scruffy like. He couldn't walk past a penny and not pick it up."
He was not universally admired, but he was certainly noticed. One friend said that you either loved or hated the man. Everyone he knew was given a nickname - one friend was known as "lunch bucket". Another friend, Jeff Bridges, recalled that he liked to be provocative. "He was a man who enjoyed pushing people's buttons," he said. "He looked like a homeless person, not a millionaire. He failed the school of social graces."
A neighbour went further: "He was a controversial figure and could be very loud. He was like the Howard Stern of Guerneville."
Others recall his acts of generosity, such as allowing people who were HIV positive to live rent free. He made his fortune from gay bars and property deals in California and Hawaii. In the early 1980s he converted his first drinking establishment, The Early Bird in San Francisco, to a gay hang-out and it became a roaring success.
From then on the money came pouring in and he set up a string of bars, including the Early Bird mark II in Guerneville. The small town, set on the banks of the Russian River surrounded by Redwood forests, has rapidly become a popular weekend retreat for people wanting to escape the hurly burly of San Francisco.
Hans Grahlmann made a mystery of his own sexuality to baffle, or wind up, fellow drinkers. "He would go into a gay bar and pretend to be a homophobic redneck - and vice versa when he was in a redneck bar," said a friend.
His early history was also uncertain. Born in Germany, he trained as a chef in East Berlin until the age of 18 before moving to Kansas in 1959. Here he is believed to have worked in a restaurant or hotel for his uncle. His German connection only emerged after he died without leaving a will. His fortune was passed on to his 80-year-old mother, Hildegarde.
But in August the elderly woman also died, leaving her money in a trust to take care of her 60-year-old son, Grahlmann's half brother, Dieter, who is mentally disabled and living in a care home. In her will, she decreed that after Dieter's death the remainder of the estate would go to the Lutheran church in Germany.
It was at this stage that one of Grahlmann former business partners and friends decided to get involved. Peter Hackett, an Australian-born businessman, recalled a series of stories told by Grahlmann of a long lost family. "About a decade ago Hans first told me that he got married to an English woman in the early Sixties. He was living in Kansas and actually referred to her as his wife, and they had two children.
"At some point he got fed up with the relationship, they had an argument about her drying stockings over the stove. He went out for a drink and basically never came back. As far as I know he never saw them again. He told me that shortly after the split his wife and kids moved back to England. I can't see any reason for him making it up."
Hackett set out to confirm the existence of Grahlmann's English family, and last month launched what the American press had dubbed the "Hunt for the Heirs". His interest is not entirely charitable: he is also claiming $175,000 (pounds 110,000) from Grahlmann's estate for what he says are joint business ventures. Uniting the former Mrs Grahlmann with her fortune would certainly help his case. Mr Hackett is also in the middle of a legal dispute with the administrators of the estate, who he described as "vultures".
He enlisted the help of Kenneth Crutchlow to set up a press conference in London last month to appeal for the heiress to Grahlmann's millions to come forward. The story made headlines throughout the world, but so far, no rightful heiress has been found.
"I thought I'd be swamped with calls from people claiming the money," said Mr Crutchlow. "So far I've got one call and that was from some guy who'd obviously been drinking. We're still hopeful that someone will recognise the story and come forward. We expected his ex-wife to come back to England, but she could still be living in the USA. She was quite poor when she split up with Hans, so I'm sure she'd be shocked to discover he made millions," he added.
The Hans Grahlmann story has been aided by an Internet web site - oceanrowing.com/hans and oceanrowing.com - dedicated to the man and the search for his relatives. Visitors to the site are treated to the sound of John Lennon's "Happy Xmas (War is Over)" and a selection from the Grahlmann photo album, all featuring a beaming Hans. There are pictures titled "Hans with his beloved Rottweilers, Bubba and Lady Berra", "Hans and his best friend Otto on the third floor of Hans' hilltop estate along the Russia River", "Hans in Mexico with friends", "Hans with beloved `Stumpy' [his dog]", and "Hans feeding pigeons along the coast with one of his collections of Mercedes".
One of the best leads has been Grahlmann's social security number which reveals he was in Kansas in the 1960s. The team hope they will be able to establish where exactly he lived at that time, and even the identity of the uncle for whom the young chef worked on arrival in Kansas.
A press conference last week in Kansas City, Missouri, flushed out a handful of would-be millionaires. "I have had a lot of people coming to me who were born at about the same time as Hans' children in the area of Kansas, but most of them were adopted," Mr Hackett said. "There is one possible fellow, whose mother is English and whose father was a cook. He's not sure about the father's nationality, but does know his dad abandoned the children. I've suggested he contacts his mother and finds out his father's name... We're talking about a hell of a lot of money here that's just waiting to be claimed."