Does anybody know of a source of tall guard screws that can be filed and indexed for proper orientation after inletting. I have checked all the usual sources including Wisner's. Any help would be appreciated, need 2-3 sets.

Michael Ullman makes "tall boy" mauser screws, call him and see if he can either make tall Pre-64 guard screws or has plans to make them, he has the equipment. Duane Wiebe might be another source.