Update
Well the visit to the motor rewinder was an experience! Lots of sucked in air and comments like "I've had hundreds just like that – can't be repaired – no parts available past or present" after a bit of time he said I could help myself to any parts from his scrap pile. So eventually I found one similar to mine with a smashed base but the top box was (almost) complete. Got it for nothing so didn't owe me anything if it was no good.
Back home and a rummage through the recycle bin / abandoned projects and came out with a aluminium construction with a radius in two short side plates which was almost but not quite correct. On the band saw to hack off excess material and then onto the mill to 'bore' the rad with a fly cutter, then carve out a hole to clear the terminal plate, drill some holes to match the terminal plate, fit the salvaged top box and JD! (Job Done)
Insulated with thick card inside and earthed correctly.
Shaper is now just waiting to be wired up again.
Thanks for all those that made suggestions
Martin