Good idea or not?

You flip a right handed bass upsidedown? So the strings are next to you body, or so the bass is in a left handed position? Having the strings next to your body will affect the tuning. Otherwise it won't hurt anything.

 

Looks like you just happen to have a left-handed bass.
(which is a G&L SB-1 or SB-2)

 

Okay, so you got a bass with a reverse neck. It won't hurt a thing. It does however, prevent you from installing a drop tuner, Because your E is now above the A and the drop lever will hit the top of the A tuner preventing you from using the drop.

 

Inline tuners are easier to use when they're on the bottom. I like reverse headstocks. More ergonomic. Leo's biggest mistake, imho.

 

Biggest mistake?
worse than selling to CBS?

 

Yep. If he hadn't sold to CBS there would be no MusicMan or G&L. And being the elephant in the room there would have been no incentive to make the improvements he did at MusicMan or G&L. His underdog status supplied all the motivation he needed to make the improvements he did.

 

I believe Leo would have come around without selling Fender.
Or maybe he sold to raise enough cash to retool and update.
Or maybe to make just enough improvements he could legally control the employment of those performance improvements rather than chasing down folks building dimensionally identical basses save the headstock profile.
But imagine where we’d be today without the ability for anyone to copy and modify his original design without the pressure of making it profitable.
Never studied his life so it’s all speculation on my part but he just always seemed like someone who was never truly satisfied with his work. As one such individual, i know i’m always looking at ways to improve. When i was having toy race car parts made i was constantly looking for ways to improve both the product and process.

 

The headstock design Leo used was used on some German made classical guitars in the late 19th century and even some Martin's. I think he was looking for an existing design that was easiest to make (no scarf joint or V joint at the head).

 

It doesn’t hurt to have the tuners on the bottom but personally I don’t like that look. Personal opinion only, not saying it’s wrong, if you like it that’s all good.