Yamaha RBX375 - mounting a preamp in a crowded cavity?
 

Here's my dilemma. I'm ditching my Yamaha RBX375's preamp for a homemade MM clone preamp, made according to SGD's corrected diagram. The board is populated and soldered, the changed pots are ready (the blend remains the same, I might float the grounding contacts to see how that sounds), but...

The electronics cavity is small. The current preamp consists of two boards, one on each of the tone pots - that's how it fit inside, though the ribbon cables between them are a mess. Even when I remove the preamp, I won't be able to mount it any way other than vertically so it's orthogonal to the fretboard, which doesn't make me happy as I've no way of fixating it. At least the battery has its own compartment so I don't need to mess with that much.

However... how much sense would it make to make a mounting point on the cavity cover and mount it there? I could fashion a non-conductive spacer so the board is off the cover by a few mm, and since the board uses pin headers it should in theory work - and wouldn't touch any pots.

Is it a good idea?

Not really any reason not to mount boards on the cavity cover, if that's the only thing that works. It will perhaps make future cavity work slightly more difficult, but it ought to work fine.