Brad,
Thank you for your reply, I especially like your comment "measure twice, glue once", I think that''ll be my motto for this project.
For adhesives I've got some 2Pack Epoxy both 5 minute rapid set and 30 minute set, they have been for fixing the plastic sheeting to the MDF.
For PVC to PVC I've got some "Pipe Weld" (a search on Google suggested it) I've not used any yet though. I've also got a tube of 2Pack rapid set adhesive for plastics althouigh your suggestion of contact cement sounds much more appropriate.
My other solution is much more old fashioned...Nuts and Bolts, which may be the best solution.
Up to now I've been very good with materials as there has been hardly any wastage, so I'm a bit angry with myself for throwing money at environment destroying glues that I can't use.
Anyhow, today I've taken the afternoon off and am doing some wiring and applying primer to some of the parger parts.
More images very soon.