Well, I know very little about them, I know they are pretty rare, I own one and there are a few others out there who do as well. Gotta post a pic to get a number! Mine is a 1978 (ish) 5 string neck through. It also has a Quantum style headstock. According to Geoff, they did not make them, but I have one. It has a Bartolini pup system. I spoke to bartolini and they do not have any spec's on my system and there are no records on it.