[69L72RS]

I bought one last month for $150, and it has a fresh 10-10 turn on it.
There was one on Ebay last week for $199.
I had two of them in the GM boxes that were over the counter service parts from the 70's and sold them for $350 each a few years ago.

I would have to agree with Jonesy about there being more than 602 of them made.

I hope this might have been of some help.