There is room for debate what makes this a Custom Shop other than the fin, given that there is no other variance to a regular model. But then that is a fair question with Firebirds too because the Custom Shop neck thru construction is the same as a Gibson USA one on F- and T-Birds. It's not like, say, an LP where (with the guitars at least, don't think they ever bothered with the few LP CS basses they did) the body-neck connection is different and more elaborate with the CS models (longer tongue and more wood contact in the cavity) which does affect sound.
So with a specimen like this one we are probably left only with longer aged mahogany and more attention to detail, fretjob etc.
