Is there any way to make a bass look more vintage? In other words, increase the amount of wear on it to make it look older? Like the Jaco Relic Jazz bass. Anyone? Buhler? Anyone?
The above is just too much effort...instead, lend it to the 10 worst, sloppiest guys you know. Trust me, not even dragging it behind a car can do as much 'relicing' as your 'friends'
The way that most "relicing" is done, both by the Fender Custom Shop and others in the business of aging, is usually done with a set of keys and/or a handful of belt buckles on a loop. If you have a nitro finish, you can probably get some finish checking by submitting the instrument to extreme changes of temperature (cold to hot, hot to cold), and taking some super-fine grit sandpaper to the back of the neck could help give the neck a more "played in" feel by removing some of the finish (without removing the finish completely, etc.). Just a couple of ideas.