There's one here,
ELECTRICAL
1. Grey Third brake light with harness and mounting bracket ---$30
http://www.turbobuick.com/forums/parts-sale/332100-large-parts-list-come-get.html#post2622252
GN Luver,it seems that from the vin you posted 1G3GR1197HP318935 it is a real 442.
View topic - 1987 Olds 442 Priced TO SELL FAST • GBodyForum.com - '78-'88 GM G Body Community