Thanks Timothale, I'll check those sites out more. That rolled edge in the pic on Wray's eBay store is a doozie. Looks like a "two pair of welding gloves" tool. Anybody know of a complete crimped edge disc, or is this all that's available.
I'll check out Home Depot or Lowes as you suggested, but I'll have to come up
with a way to make that recess in perfect center. Something to think about for sure.