You need to find one from a place specializing in NOS parts. I'll search parts voice for you and see who (or if anyone) has one.

Is the part number you posted above the part you need for sure?

Just checked the superceeded # and three places have the part:

GALEANA C/P/J
Columbia, SC 29210
(803) 461-7700

Pioneer Motor, Inc.
Trinidad, CO 81082
719) 846-2264

This place is hella expensive, so be forewarned:

COLLECTORS AUTO SUPPLY
OROVILLE, WA 98844
9800) 414-4462