If you are truly willing to spend $3K for a PSA 1 Mantle, why not buy a PSA 5 for that price.
There is one on ebay right now with a Buy-It-Now. I don't know the seller at all. I just saw the card listed.
Here is the link:
http://cgi.ebay.com/1951-Bowman-Hall...item2eb22589b0
I would actually send an E-mail and ask him if he'd take $2,500. If he says no, then Buy-It-Now.
Cy