There is a potential opportunity to grab a nice (modern day) jazz Gretsch kit with an 18" bass drum. It would be cool to have in addition to my RB with the 20", but I don't care for the look of the new ones, so I'd be looking to have it modified with old style hardware and probably a different wrap.

Has anyone done this kind of thing and would it be feasible (a pro would do it) without seriously messing up the drums? The reality is that a RB with an 18" is impossible to find, so...