I would like to convert a Harley Benton PB-Shorty SBK to fretless.
The plan:
The neck width of the shorty is 42mm, the new saddle is 40mm. I really want to use this saddle because I have it on all of my basses and I’m super happy!
So far I have always ground down 40mm to 38mm.
Question: can I easily use a 40mm saddle on a 42mm bass?
The bass:
The nut:
I don’t see why not, though you’d miss out on wider string spacing if that matters to you.
No, in fact, since I use 38mm nut basses I got quite used to that. Love that size!
I’d probably suggest swapping out the bridge as well for one with the same spacing as the nut but it’s optional really, it will make only a very small difference.
Ah, I completely forgot: yep, I have a Fender Highmass that is looking for a new bass!
I’d just buy a fretless bass.
Hahaha! Yeah, that’s an old discussion - waiting for @MikeC and @Barney to comment on this one 
The cheapest/ok short scale (!!!) fretless would be the Sire Marcus Miller U5.
I had the fretted U5 here, and it was ok. But not great!
Modding is fun, and the Harley Benton PB-Shorty SBK has a similar body (though not the same neck, unfortunately) as my Harley Benton MV-4MSB. I absolutely love that bass more and more, every time I play it!
Also, it’s @Paul_9207 's fault. He started it (the fretless modding, that is ^^).
He started it with a bass he had laying around though. If you’re starting from ground zero, I’d just save up and get the Sire.
Hmmmm … the Harley Benton PB-Shorty SBK costs 119€ and I have all other parts in a box, doing nothing.
That counts as “laying around”
Also I can start a new thread “Should I shoot my FRETLESS bass?”
Yep. The only thing I had to buy for that project was sand paper and paint.
If you have good skills any quality pulling pliers should work just fine. You’d need a good heat source to melt the glue. Small and thin wood saw would help with the cleaning.
I encourage you to buy a use cheap even damage ukulele to practice pulling frets. The learning curve is not steep but there’s a learning curve.
This reminds me of the old joke about Linux - “This OS is only free for people whose time is worth nothing.”
That’s me!
