Vince Lupo
Whatever
Vince, here's a similar early-type finder currently listed on That Auction Site:
https://www.ebay.com/itm/304684720633
My 500C dates back to 1966, but I purchased the finder separately, and I deliberately chose the older style because I thought I wanted my camera to have more of a vintage vibe. But be advised that this design has some tendency to pop apart at the hinges, and I've got the main hinge pin of mine held in place by tiny drops of clear JB Weld. It's too soon for me to know whether this is an effective fix or not.
I’m always amazed at how much the waist-level finders cost - I think they should be about half that.
I have a very early 500c (the 647th one made) and I’m looking for a finder like that, but I’m hoping to find one for under $200. Ah well a boy can dream….