I can't say what Greco might've used in '87, but I know the '89 that I drooled over for a couple months before it finally sold (also on Reverb.com) and all other Greco T-birds that I've seen (which have been newer than '87), utilize a 3 point with a claw tailpiece.What sort of bridge is standard on Greco Birds?
There's one for sale on Reverb at the moment and the bridge is not what I would expect to find on a GSO.
Greco Thunder Bird Bass, Black, 1987, Made In Japan, HUGE LOW END
1990 Greco Thunderbird IV TB1100 Electric Bass Guitar Japan Fujigen w/ Gigbag
