Here is an ethernet adapter for any Macintosh with a NuBus slot  This was made by Asante in the mid-1990s.  I recently removed this item from a Mac IIcx. 

The end of the card has an RJ45 port for 10-Base-T ethernet and a DB15 port for an AUI tranceiver. 

Buyer will receive the exact item pictured here, without any cables or software.

I offer a 30 day return privilege and free shipping to any U.S. zip code.