Not a 60-66, but a cool old monster GMC tow truck for sale I found on the westen slope of Colo. ---Not Mine, just thought it was a cool old tow truck.
1956 GMC TANDUM TOW TRUCK. 95% RESTORED.20,000 POUND WINCH.A NEW 454 BIG BLOCK GAS MOTOR. PRICE IS 5,000 OBO. PLEASE CALL 970-691-3111 FOR MORE INFORMATION OR TO SCHEDULE A DAY TO LOOK AT IT...SERIOUS BUYERS ONLY.
http://westslope.craigslist.org/cto/2576382041.html
Hopefully someone saves it....