Vagcat won't have it. It's off a North American version of the Golf. They don't list ANY US-Specific parts.
from 1985-1992, all black interior parts were suffixed with 01C. So, your part number is actually:
176.857.237.01C
1stvwparts.com lists that as a viable part number, but they show it as discontinued. There may be some old stock somewhere, so try calling your local dealer and see if they can locate it on vwhub. Be sure to tell them to NOT look only in their local stock.