Below are inks to web sites where accessories, spare parts and useful tools can be purchased from.
Remember though that in many cases other than 'Windsor contract' and 'L.A.Co' P53 rifles that the individual parts were made in many factories in varying locations so many pieces (such as screws and lock plates) are not a standard size.
UK - Enfield / Snider
Jeff Tanner (bullet moulds)
WD Ordnance (original parts)
Midway Uk (shooting accessories)
The Leather Workshop (Leather restoration and products)
North America - Enfield / Snider
Accurate Moulds (bullet moulds)