needs provenance,....
without provenance - whatever you can get
with provenance - well, if I didn't like spending money on cars or boats or grandchildren a bit more than I like spending it on keepsakes I'd give you 500 dollars just to put it up on my office shelf (I have the Y, the A, the E, and the C off an old long gone turbine building on the side of my shed), I would be willing to postulate there are a few folks with Argonne roots or some other connected history who might pay more, the trick is getting the word out to those select few persons,...
as to CP-1 original folks?!?! - not likely they're still above ground,....