The seller for eBay item # 250445866736 has a complete 3420 tape drive
and 3803 controller available. Located in Ladysmithc, Wisconsin. They
are due to be parted out if no one speaks up for them.
I inquired about these, and the seller sent me some photos. They are
posted on my website at
http://www.harlie.org/ibm_tape .
I do not collect IBM big iron myself, but the 3420 is iconic, and folks
look for them from time to time.
I have no connection with the seller.
--Bill