In rebuilding and restoring a 1942 Steinway B keyboard, I was able to perfectly (and tightly) space the keys by replacing all the key's front rail mortises. Although I custom fabricated the new mortises, the inspiration to do this work came from Mike Morvan's excellent work at Blackstone. Replacing the mortises has, I believe, improved upon the factory specifications and it was easier (and more accurate) than trying to either move the front rail pins or replace the front rail.

I hope to share more of these rebuilding experiences soon.