I put a Status fretless neck on a regular Fender JB (American Special series). The result sounds and looks great :-) (see picture), but was very hard to get! The Status neck was to thin and didn't fit in the bass pocket, the bottom of the neck (in contact with the screws) was not flat enough, the holes for the machine head mechanisms were to small.
I had to send the neck back to Status for modifications and once again the neck didn't fit! Discouraged, I had to ask my guitar craftsman to do the work (with an extra cost of 380€...). On Status website, Rob Green says: "Our P and J type necks are designed to fit on all regular Fender style basses with 20 frets". Sorry but that's really not true in my case!
Great result at the end, but much more expensive than expected and not easy to get!!!! And I had to wait 4 months to get this neck on my bass.
Anyone had this kind of problem?

I've heard of one or two problems but also plenty of stories of them going straight on too.

Part of the problem is that Fenders are mostly built to the same specifications but there are few models that are different, the Japanese Fenders particularly (although they're some of the best sounding and playing Fenders for the money IMO)

Fender have used various different sized and shaped tuning pegs over the years and on different models, some of them don't even tune by turning the same way.... very confusing if you're on stage and it's all sounding a bit wrong :o

Sorry to hear yours was hard work, hope the end result is worth the extra cost and effort, it certainly looks the business!

Oh, and welcome to the forum!

Edited: to make some sense!

Might have been a hassle but the result is pretty stunning. Good job.