Casting number is 3929698
Just like this one on Ebay, but cleaner:
https://www.ebay.com/itm/Chevy-Small...sid=m570.l1313
The guy on ebay obviously doesn't know the difference between a damper and a pulley.
All you have to do is pay shipping. Not sure if it fits a medium flat rate box, but I think it will, which would make shipping less than $16.
Pictures attached are of the actual part.
Removed from a 1972 C50. Perfect condition.