I have a '76 Rickenbacker 4001, and I've never had a problem with the lacquered fingerboard. I think it still looks great after almost 30 years ... no cracks whatsoever. Of course, I take care of it, and the previous owner(s)obviously did as well. And, I must say, there's no bass on the planet that sounds like a Rick, not even an Alembic. This is both a good and bad thing IMHO. I find I can't use it for stuff requiring a more rounded, jazzy tone, but for the rock, high treble type stuff, with a lot of punch, it's awesome. Anyway, I played Ricks in high school, so I keep one around for nostalgia's sake.
My '73 Jazz recently went through a re-fret, and had to be re-sprayed. It's one of the black block inlay maple necks, and the only reason I got it re-sprayed was due to the need for a refret. Personally, the dirt and grime doesn't bother me much, but I can see where it might bother others.
Now, my '74-'75 Ripper is another story. Lots of lacquer checking on that one, but oddly enough, it plays extremely well, and has a unique sound. I'm almost tempted not to have it refinished for fear of ruining it in someway. It's beat, lots of nicks and scratches, but it's just a beast and I love it.
My '79 Musicman is in for a refret as well, but only due to some problems with the neck. Apparently, the truss rod can't be adjusted enough to make the upper part of the neck straight where the frets won't buzz. Basically, it's like a ski ramp, with the upper part of the neck bent up a bit, requiring a planing of the neck and a refret. Oddly enough, the finish is still great after 25 years.
Of course, none of them is an Alembic. 'Nuff said.
Alan