Finally got the playfield out and into my home-made rotisserie.
I searched all the usual hardware places for pipe unions that everyone else seems to have sourced, but no luck 
I had some 25mm & 30mm tubular pipe off cuts spare and went to a steel fabricator for some 50mm wide flat steel. (Off cut cost me $2) The meccano style strips were from an old basketball board support.
After a couple of hours cutting to size, a mig welder and couple of old poker machine bases (good for parts storage underneath) this is what I came up with 
I’m thinking this thing does not need to go over 0.1RPM and the welded nut and securing bolt allows me to fix the playfield at any angle.