Old school for sure.
But a skilled operator can still do a damn fine valve job with stones.
Agreed, but the trick is finding the "skilled operator", and the public won't pay for him (or her?) or the greater time it takes to execute the quality job expected.
But every once in while I'll pull our Sioux seat grinding set out to use on some obscure job, or even after utilizing our Sunnen VGS20 or the Peterson TCM-25 when I what to lay down a texture remaining from the carbide cutters on some unfriendly seat material.
Scott.