The 52-year-old former pistol champion runs his business from a workshop next to his house near Salisbury, Wiltshire, with the help of his 27-year- old daughter, Rachel. Of the five pistols he was working on this month, four customers have rung up and cancelled their orders since the Government announced the new controls. "One of the guns was 90 per cent finished," he said. "I've got one more Matchmaster gun to finish for a guy in Jersey and that will probably be the last one I'll ever make."
A mechanic by training, Mr Westlake spent 25 years in the Royal Electrical Mechanical Engineers where he was five-times Army pistol champion. In 1980 he made the Great Britain team competing in the World Championships and Commonwealth Games and six years later became a national coach.
He learnt his trade working in the small-arms section of the regiment and after leaving the Army set himself up as a gunsmith making .22-calibre competition pistols at pounds 725 a-piece.
As his reputation blossomed, he went on to make larger calibre pistols, mainly .32 and .38 handguns - both of which are set to be outlawed under the new government ban. Although .22 guns will still be legal, the stringent ownership rules outlined in the Cullen report and the possibility of a total handgun ban under a Labour government has meant that the market has dried up. Mr Westlake gives his business two months' survival time.
"I have no income, end of story," he said. "Every penny that I spend comes from my savings. When my savings go I'll have to sell my house. It's no good saying to me go out and borrow the money because if you were a bank manager would you loan money to a gunsmith at this time?"
Mr Westlake believes the estimated government compensation package of pounds 1bn for members of the shooting community who lose out under the new legislation will be too late for the pistol-makers. "We could be talking three years before the compensation comes through," he said. "I'll be finished by then."
The proposed new legislation has also had a devastating effect on Mr Westlake's family, particularly his daughter, Rachel, a qualified gunsmith and part-time helper, who runs her own fashion-design business.
"What has made me so angry is that various people in the local media have referred to my father as a killer because he makes guns," she said. "It's extremely hurtful and actually quite frightening that people can think in that way."
"These people do not know what they are talking about" Mr Westlake said. "Guns are not weapons, they are sporting goods ... A gun on its own never killed anybody. It requires somebody to use it to be dangerous. You don't blame the gun, you blame the person."
He accepts that tighter gun controls are necessary but feels that the Government was edged into a corner by public hysteria after the Dunblane massacre. "Thomas Hamilton felt rejected by the shooting community and he is getting his own back on us from the grave," he said.
Mr Westlake is considering moving to the United States but in the meantime is channelling all his efforts into promoting the newly formed Sportsman's Association of Great Britain and Northern Ireland, a pressure group fighting the ban which in just a week has recruited more than 6,000 members.
For Mr Westlake, battling for the gun enthusiast takes his mind off the demise of his profession. "It's a sad day when you realise that your skills are no longer required in Great Britain," he said.