So that's your oem master and hold-off valve? Never seen a BA stamp look that good, nice parts! I think you'll find a pretty easy time of rebuilding your oem calipers. The kit costs aruond $15 and it's fairly easy. If you find a small amount of corrosion on the inside of the caliper housing, no worries, just sand with 600 wet, and clean it up. Great progress so far.