126 seat reupholstering

Dear Friends,

My old man's 126 (1986 380SEL) two front seats and rear "bench" need some attention. A few questions:

I've intertwined 12 coat hangers through the rear "bench", tightening it up considerably. Do you think this technique will do the trick on the front two seats?

How do I remove the front seats without damaging the electronic mechanism that moves the chair along it's tracks?

Where can I obtain the padding (cheaply if possible)?

Finally, does the padding have to be fire-proof?

Thanks,

David Rayment.