Peter Smith’s project began in 1977 with the Silver Jubilee so it is more than fitting that it should reach its culmination this year with Her Majesty’s Diamond Jubilee.

Peter has dedicated his spare time to the making of intricate, exquisite miniature Royal State Coaches and he will be showing the best of these as part of the Diamond Jubilee Celebrations at an exhibition in aid of Harrow Churches Housing Association.

"There will be six of my ten coaches on display," says Peter, who is '65 and a half’, "three of which are the Irish State Coach, Queen Alexandra’s State Coach and Prince Philip’s Park Drag, a coach they now use for shooting parties.

"This is the only collection of models ever made directly from Buckingham Palace coaches and they’re up to the international gold medal standard at the international Model Engineering Exhibition, in Olympia."

Peter will be on-hand to explain to visitors how he has had permission to go into Buckingham Palace and Windsor Castle more than 40 times to study, measure and photograph the royal coaches.

"People just stand there open-mouthed," Peter laughs, "they can’t believe they’re handmade!"

The model coaches are made of beech timber, birch ply, glass and steel and Peter uses silk for the upholstery, roof linings and cushions and leather for the roofs.

"Everything is as close as possible to the detail on the full-sized coach," Peter says. Each one takes approximately two years to complete and he works from around 50 photos and 40-odd pages of measurements taken from the originals.

Peter has won 49 awards for the workmanship that goes into his miniature coaches at all the biggest model engineering exhibitions and more than 25,000 people have seen them so far this year at the various exhibitions he attends and talks he gives.

But his most special viewer is Queen Elizabeth herself. Peter has shown his Royal Collection to Her Majesty twice in a private audience, one of which was also attended by Prince Philip.

"The Queen couldn’t believe them," says Peter, from Bourne End in Buckinghamshire. "She was very knowledgeable about the actual coaches and compared all the details. She opened the door of the Irish State Coach to have a look inside and then said to me that it was the first time she’d opened a door in her life!"

The Royal Collection is at Ewart House, Richards Close, Harrow on Friday, June 1 from 2.30pm to 5pm. There will be live music and the Mayor of Harrow, Cllr Nizam Ismail, and his wife will be in attendance at 2.30pm. Everybody welcome. Details: 020 8426 4995, www.hcha.org.uk