It doesn't bother me. I have a few other basses. I think I have been sold lol on keepingIf the lack of frets bothers you, or the current fretless isn't playable/your cup of tea then a neck swap is easy enough.
I'd address the playability first, but I dig the look. Like Max said I'd never try that with one of my basses, but now that its done I'd rock it proudly!
You can be sure nobody else would have that exact same bass.
I kinda want to know how the previous owner did that paint job. Very cool. I'm not a big fan of pickguards, but I agree with the other comments that one here would balance it out nicely.
I say get a fretted neck and swap between the two when the mood strikes.
It looks like they carved the new contour around the body in the general shape of the pickguard. Left imperfections in the sanding of the wood to help the color layers pop.
Then layed down 10 to 15 thin coats of different colors and in different areas and sanded in different areas to different depths to get the finish. Then cleared it. Totally a guess.
Thanks for all the feedback everyone!!!