Just in case he has not been mentioned yet:
Max Ern (and family)
Bergische Landstr.87
51375 Leverkusen
Germany
http://max-ern.com

Max Ern builds finest rifles to order, He builds S/S and O/Us, both boxlock and sidelocks, most with rising-bite lockup. They do their own barrel rifling, lockmaking, casehardening and engraving too. The website is in English too.