Sounds to me like it might have been the mating surface on the stub axle that was at fault rather than the discs themselves?

I can't remember why, but I removed my discs about 15 years ago and when I replaced them I had a dreadful pulsing through the brake pedal as if the discs were warped. Double-checked the mounting and somehow I'd managed to trap a tiny bit of debris between the disc and stub axle mounting faces. Cleaned them up and flatted them off with a bit of emery cloth and some engineer's blue, reassembled and they've been perfect ever since.

I had new disks on my 4/4 last year. The garage warned me to gently bed them in & to slowly build up the heat (harder braking) over a matter of weeks, or they would warp. Apparently for track work, they only use pre bedded in disks.

I was told a long time ago that new discs were heat treated before final grinding, which reduced warp in use. I was also told that this is no longer the norm.

I have access to a Colchester Mastiff lathe.

Can skim a complete brake disc in one operation, without removing it from the hub!

Arwyn

I've replaced my 2011 Plus 4 standard set up (pre industrial revolution Austin Westminster or something similar) with Mulberry brake kit which is all Hi-spec parts, about 8 years ago. The calipers are 4-pot and the discs/bells are 2 piece. The discs are 312mm diameter if I recall, and with Mintex MGB522 pads give a lovely feel under foot and great stopping power. I did buy a spare set of discs for future, which will of course bolt onto the existing bells, but this shouldnt be for a while given summer use and almost sensible driving. After 20k there's no lip on the discs and the pads are bearly worn. I remove the pads, clean and grease every 2 years. After driving my Exige with AP Racing 4-pot set up I didn't feel the standard offering from Morgan was upto spec.