I'm using my old soldering iron to smooth out and weld some of the gaps and obvious joins which explains some of the black marks which is carbon from the iron despite cleaning it quite well.
I didn't leave enough room in the cavity for the neck to sit into but I can cut some more out with my Aldi dremmel or cut/drill a slot into the neck area going back into the cavity along its length using half the height on the bottom to slide more timber into the body.
While I'll keep working on this I'm going to go back into the files and redo the design so things are a lot simpler and it is all one object, rather than the squashed together nightmare it turned out to be.
I maybe able to just bring it into software I own and just retoplogise it so it isn't the dense mesh that was turbo smoothed into the non quad mess it ended up.
I may try and make it more like the poster but we'll see :-)
The real ukulele is my tenor uke place there for size comparison.
The bridge will be cut down to width, hopefully the reduced surface area doesn't impact the gluing strength. (You know it will lol)
The fretboard is a cheap Chinese tenor one I bought out of curiosity a while ago, and whether i'll use it for this I don't know yet, after all this is a prototype and may not progress much further than this.