Sorry - but maybe the preservation society should be contacted. Personally if I was going to buy this or help buy it - I'd like to know how this person acquired it? Many items were removed without permission over the years.
Having worked with the BFD for over 25 years - you wouldn't believe how many times we went their and I can only imagine how many times the Buff PD responded there.
The current owner should donate it back if no clear bill of sale can be produced.
That said - if you want you can set up a PAYPAL site link for donations. That way anyone who cares to can just click and donate. If this fund drive goes forward - count me in for $25.00. -
Good Luck