will w123 seats fit a w115?

[sides]

I have a '74 240d and the driver's seat is tearing pretty badly, at least on the bottom (seat) part. I know of a junkyard with some parts and thought I'd look for a good seat - at least the seat cover. Will later model seats for w123s fit and bolt into my car?

Also, I'm looking to replace the front quarter panel on one side. Any experience with this, or links to it? I've heard they're put on with an adhesive that's hard to deal with.

Many thanks.