Cartridge boxes, artwork, bullets, loading are all the easy part. Hell you can make the boxes by hand if need be and cobble the rest together with a bit of effort. Biggest challenge is the brass head stamp in small quantities. Quality cartridge seems to be one of the places that can do it but someone would have to check how much for how many, and I doubt it would be cheap but it's worth a look see. Bertram Brass is another option but I've heard their brass is marginal and expensive so I wouldn't bother with them.