[69GP1]

Here's the GM set for ~ $900 (priced as each):

http://www.opgi.com/p/wheels-tires-a...3/PZ00925.html

These have the inner groove on the edge of the square lip and are 3.25" deep. It still doesn't look to have a stepped lip, although they describe it as such.

Those ones below from ineedahupcap.com are advertised as 3" deep and shown with the stepped edge, but that's not what they sent me. This is the third set I bought (from various vendors) and didn't get what's in the picture! I'm refusing to pay return shipping this time, and waiting for their reply.

[69GP1]

Update - I found what I believe to be original USA-made 15x8" Corvette rings at Heartbeat City for $134.88 each. I asked if these are the GM #3923626 but he didn't know the GM number. I had him measure them, they are 3" deep from the lip straight down, and 3.25" along the angled surface. The aftermarket 3" ring I tried left a .25" gap, so these should be just right.

Even better, they had a holiday sale which gave me 15% off, so they were just under $500 shipped to my door.

They don't have the stepped edge, but they have a groove around the lip, right at the edge. I think this is going to be the most correct ring for the pre-'73 15" Rally II:

http://www.heartbeatcitycamaro.com/s...-15x8-GM-each/

It's a lot of money for trim rings, but much better than other places charging twice that... and the same rings on eBay (in NOS GM boxes) are as high as $1200.

I'll post again when they arrive and I try them out.