I didn't realise that new steels came with the frictions. That's a good thing.

with those thicker steels and contact did clutch even release? It would also b overly stiff if in fact springs didn't coil bind I would guess. I'd use OE steels as Mark suggested as being an oil clutch warpage probably a non issue, sand 'em up & swag (sientific wild ass guess) tells me it'd all be good

Thanks everyone for your help and suggestions!

Quick update - we swapped in the old steel plates after a good cleaning and scuffin'. All is well. Clutch works perfectly now, no more contacting the side cover, no more scary noises.