I have seen bass players with amazing gear and not the slightest idea how to use it.
I have seen bass players with relatively mediocre gear making it really work.
Having the worlds best bass will not transform someone into the worlds best bass player.
I can see it being a massive leap of faith to get someone to build you something wonderfully unique and special but not purely to say that so and so built this for me if it looks like every other J or P bass and sound fairly much the same too, especially if you have been charged an additional couple of grand for the priviledge.
I think I would be a tad scared to take something rare, personal and unique to the sort of gigs I've played.
If I would loose sleep if it was stolen, I won't gig it.
If I couldn't take out my wonderful one off custom bass to show the to world, why would I bother getting one in the first place?
I have never had a bass custom built or had to deal with a luthier but I have dealt with various types of tradesmen/craftsmen over the years.
There seems to be very little mention of contracts of build schedules. Are you guys paying full whack up front?
Are you putting up a deposit? What?
I still have some doubts about whether a lot of these one offs aren't put together from bodies and necks that you can buy from various suppliers and slightly fettled with. You could be just forking out a load of dosh for someone to screw a neck on a body and bung some strings on it!
If, like me, you tend to play pubs and clubs, when the punters are dancing on the tables I doubt the thought in their minds is how much your bass cost and who made it.