Bonny,
Over 45 years ago I wrote to all of the then still extant British Gunmakers, asking if they had plans for their old single shot rifles. Quite a few replied but all said they no longer had them. In many instances some actions were scaled up or down in size depending on the cartridge required by the customer.
Thanks to Wal Winfer we now know a good many Gun Makers didn't make their own actions but ordered them in from Greener, Francotte etc.
Never rely on any plans on Patent Applications, firstly they are not dimensioned, second, they seldom bear more than a passing resemblance to the production item. Plans for British single shot rifles are not commonly available and people who do attempt to make them have to have access to an original action to 'back engineer'. However don't let me put you off, there's not a finer feeling that to shoot a rifle you have built yourself from scratch.
British single shot actions are not at all common, and when they do appear they command high prices because they were not made in vast numbers, except for those that were for the military of the British Empire and they were mostly Martini-Henry's or 310 Martini Cadets.
Wal Winfers books I understand have recently been republished so they should be priced less than some people were offering the first editions for a year or two ago. They are very well worth having. I wouldn't part with my set of seven volumes.
Good luck with your quest,
Harry
