I had a similar problem several years ago with an R90/6, and I got them built up with Stellite and reground. Arguably better than the parent metal. A competent reconditioning shop should be able to take care of them for considerably less than the cost of a replacement set. Just a thought . . . .
'76 R90S silver smoke
'75 R90/6 hybrid
'Skills are learned, talent is ornate.' Billie