Hi Jason - Yes & No - depends on the supply accuracy of the rails. Small rails generally are not straight. If you get the rails first you can have the machinist mill gutters vs edges and then he can ease the gutter to the rail. This will straighten the rail... If you use only one edge land for registration you will need a method of pushing the rail up to the land. Download rail makers design manuals they have all the guff on this sort of thing. Peter