The Signature models with Leo autograph on the bass horn became available in late 1988, although it took until 1990 before they were listed in the catalog. The Signature series ended with the
ASAT Classic Commemorative Edition and
ASAT Bass Commemorative Edition of which the last were produced in May 1993. For most other models, the Signature series stopped around the the time BBE took over operations for G&L around November 1991, although by exhausting left over parts from the pre-BBE era, including Signature bodies, there were still some Signatures released until the middle of 1992. All of these are USA models and have a 3-bolt neck attachment. Check out the Signature models listed on
Greg Gagliano's website.
Hope this helps,
- Jos