Marty, spotted these on ebay..not sure if you need em, but suspect that spares like these don't come up all that often.
http://cgi.ebay.com.au/Gottlieb-BLACK-HOLE-Pinball-playfield-plastics_W0QQitemZ300319458937QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45ec6f4679&_trksid=p3286.c0.m14&_trkparms=66%3A4%7C65%3A10%7C39%3A1%7C240%3A1318%7C301%3A0%7C293%3A2%7C294%3A200

My trusty google alerts picked those up for me a few days ago.

Mine are actually OK (1 broken but can be fixed).  PBR make a repo set for the upper playfield.  Lower plastics, hard to come by and if they were I'd grab them.

Thanks for the heads up tho!