Pauld

Couldn't find ray34 but the wiring will be similar.

The Ray34 should have a stereo jack socket, it's used to switch on the active circuit. The signal should come from the tip though.

Lowe custom guitars in US make a 32inch conversion neck. https://www.lowecustomguitars.com/available/

I think the tmb 5 strings are 18mm spacing. My tmb35 is anyway.

Batteries fit no problem. I've got EMG actives in my short scale, the battery sits nicely in the square bit next to the p pickup.

Nordstrand make a 51 pickup in a jazz housing. https://nordstrandaudio.com/collections/4-string-jazz-bass-pickups/products/51-split-j-1 These in a standard jazz body may give you what you're after.

I think the Mike Dirnt has a square heal, rather than the rounded one here.

You can get them from ebay, they're pretty good quality. https://www.ebay.co.uk/itm/Steinberger-String-Adapters-Headless-Hohner-Cort-Bass-or-Guitar/224125030396?hash=item342ee48ffc:g:4UwAAOSwqudfPl-K

The MM5 with the neons is Lauren "LT" Taniel. The bad taste neons must be a Beyoncé thing, cause her and Divinity Rox both use them and have played for Beyoncé.

I think they’re D’addario chromes. Mine have blue silks, and only D’addario make strings with different coloured ball ends.

It’s also got 24 frets with markers in the correct places. If it was a damaged neck shortened the markers would be out and definitely wouldn’t have 24 frets.

Leo Moracchioli does some fantastic covers in his own style, plus his videos are really entertaining to watch.

EMG HB are active p style pickups in a humbucker housing designed for the original Steinberger basses. I have them in a Steinberger Spirit. Wired volume, volume, tone. But I agree with Dood about soldering onto the barrel jack, that's how I did mine. I think it sounds like a battery problem, try changing it to see what happens. If that doesn't work double check all your connections are good and that none of the solder-less connectors have come loose.

Metallica use this style of microphone live, on boom stands.

The current Steve Harris bass has a SPB-4 Steve Harris signature pickup in it. The previous blue model originally had a SPB-1 in it, but I think that was then changed to SPB-4 also. There was also a previous model "signature" model that had a SPB-3 in it, with an Eddie on the head stock, but this wasn't a real signature. Steve Harris used SPB-1 in the past, but I think he uses SPB-4's now. As far as I know he's never used the SPB-3.