I am restoring a 1968 XR7. The body guy sand blasted but forgot to remove the brake distribution block and valve. The numbers are fortunately still visible but it may have been replaced at one time, C90A-2B091-A and the spare from the other 1968 is C70A-2B091-A. Do I look for a C80-A or does it really matter in the restoration? Will the slight sand blast damage be of concern? Any thoughts?