Well I found the problem! I guess I shouldn’t have trusted the reman caliper to have a decent surface- it was like the dark side of the moon! I know the copper prefers a nice concentric ridge to bite into it but dead flat has to be better than this!

I filed it flat until the craters were all gone and then sanded in opposite directions up to 800 grit. I figure almost polished is better than lengthwise sanding scratches. Still gotta bleed it more but it has a better chance of sealing now and if it leaks I have a set of stat-o-seals on order for the next problem banjo.

Thanks for all the helpful suggestions and if anybody works at (edit:) cardone tell your boss to clean up the banjo surfaces as part of the remanufacturing process! I’d sure pay $5 extra!