Black and Decker Valve Resurfacer Repair

Lotta those look like Sioux which are diff dia.than BD
Think I used helicoils on sioux stones in some cases.
You'll be doing 5 angle grinds in no time.
The stone holders, I call arbors, just drill out to a suitable valve guide OD, then size ID to Sioux pilots OD, - then helicoils Sioux stones to fit BD arbors..
That just makes everything you need to order Sioux, often cheaper/commoner.
I also assisted in hi-school auto shop, and found they had a box of "worn-out" stones, with many I could still use .
I didn't have internet when I brought my BD up to modern standards.
Very nice .