[David G4EBT]

Much depends on whether you want to keep the cabinet as it is. I've restored several KB FB10s for myself and my younger (adult son). I don't think I've ever paid more than a tenner for them - mostly less, off the scrapper pile at Golborne or NVCF. Some have had chucks missing from them, others, just cracks. I've invariably resprayed them, but if you want to keep it original, most of what I've written below is irrelevant.

The closest example to you're cracked one is shown in the pics below. (A fiver from Golborne, 2018).

Quite how they get damaged like that yet the dial remains intact is a mystery, but a rather lucky stroke!

Depending on the nature of the damage, I've used car body filler, Ronseal catalytic 'High performance' wood-filler, which sets rock hard in minutes, sands really well and would be quite a good match for the case and is what I'd have used had I not intended to spray the case.

As I was only concerned about making a strong repair and less concerned about how it looked, on this occasion I cleaned out the crack and used a two-part epoxy known as 'Super Steel', applying some inside the cabinet for added strength. When applied it looks black, but when sanded is a light grey colour. I then rubbed it down with 220G wet and dry and likewise, sanded the rest of the case to give a key for a high build primer. I primed the set then sprayed it blue at my daughter in law's request.

Pic 1: Shows the crack.
Pic 2: The crack filled and sanded.
Pic 3: The case primed.
Pic 4: Sprayed blue gloss acrylic.

I don't care that they never made a blue one and nor does the recipient.

Others have been pink, green and red.

If chunks have ben missing, I've bridge the gap with wire from paper clips drilled edgeways into the case on each side of the gap, then built up with filler, sanded to the correct profile, primed and sprayed. I'll add a few more pics.

(I've also restored the electronics as there's not much point in putting lipstick on a pig that doesn't 'oink'!)