This is an very nice, used factory external oil thermostat assembly (stamped 911.107.163.OR). Threads are in great condition.
I replaced the internal thermostat with a brand new unit (Hella/Behr) and sealing ring, since this was going to go into my resto:
930.107.155.00 - Regulator Piston for Side of External Thermostat (Hella/Behr)
900.123.136.30 - Sealing Ring for Regulator Piston for Side of External Thermostat
I also replaced the (terribly designed) original thermostat cap with a beautiful new one from Pelican "JimmyT", which provides a metric hex for easy removal and tightening. For more info on this aftermarket part, please see the thread HERE.
This assembly has not been used since the new parts were fitted.
$250 plus shipping, or can be collected in San Diego.