If MG Magic doesn’t come through consider buying a roll of marine carpet and cutting that to fit. That’s what I did on my car and a decade later I’m still finding new and fun uses for what’s left of the roll.
I also tried to make my own door cards but that didn’t go well so I got a real upholsterer to do them right and to match what the original TDs came with.
That was like $200, but a while ago.
Be aware: the original TD reproduction door cards from Moss Motors do not quite fit our replicas.
Good luck!