Thanks for the link - I can get a new block cast in 'lemon brass' by Kevin Blackley in the UK and it is no problem for me to make the pattern, but I don't have any drawings or photos of the internal parts of the catch system and I would like it to be more or less authentic. I didn't realise how much...

I recently bought a Greene's Rifle Works 1864 Carbine - a fairly unusual carbine out of the 20 or so breech loaders that were patented around the Civil War. It is without its brass hinged breech block ( should be a bit like the Snider) and I want to make a replacement. Does anyone have one, or know ...