With the woofer enclosures now looking pretty good it was time to tidy up how the compression driver is supported, and tidy away the LPAD and protection circuitry.
I got some small pine boxes of the right size (from ETSY seller HIPROGRESS. I stained this the same colour as the speaker boxes, and got some self adhesive 4.5mm neoprene sheet from Clark Rubber to act as vibration damping, and protect the finish. This acts as a nice firm bed for the compression driver.

I got some 12AWG speaker cable and banana plugs from Selby Acoustics to redo the LPAD and protection cap wiring, mounting them inside the box with the cables threaded out through a small hole. Now the whole rig loooks a lot tidier. I was originally thinking of making a wooden enclosure for the waveguide, but I quite like having the compression driver and horn exposed, and they look OK now that the wiring is tucked away and the bricks are gone.

before:

after:

mounting the parts in the box:

some dabs of hot glue added after to keep it in place and stop the components rattling about.