I found half of one: http://www.ebay.com/itm/Vintage-Mac-SE-MacCon-SEE-Asante-Tech-P-N-09-00300-61-Rev-A-Apple-/400643429539?pt=LH_DefaultDomain_0&hash=item5d483594a3

This is the correct board, it's a MACCON SE, but you'll need to find the transceiver portion...