I only buy Davis or Jim Chambers locks now because I had some serious quality control issues with L&R a couple of years ago - particularly with their flint locks. Percussion locks are less finicky but I still prefer Davis or Chambers unless I cannot get the style I want anywhere else than from L&R. Having said that, when I did send an unsatisfactory lock back to them, they did replace several parts and returned it to me quickly and at no cost other than my postage to send it to them.
Pecatonica River Long Rifle Supply gets full marks from me for excellent service over the past 5 years or so. Although they stock a wide range of parts and can provide kits of various styles, their real forte is producing very good stocks - I believe they mill stocks for a number of other vendors too. Don't hesitate to phone them - they are happy to discuss your needs.