Hi Alex, welcome to TM and to the wonderful world of Morgan ownership with all of it's highs and lows!

I have a 2009 S4 Aero and have my "work" done at Techniques up near Stevenage. They are very familiar with Aero's and I've certainly seen a Max in the workshop.
The wiper blades are a constant pain, most owners of all models seem to complain they are ineffective and difficult to get to fit well.
I think the screen is bonded in place, so is a major job to replace and I think getting a heated replacement is the issue.
The rear window hatches on the Max were subject to a revision, to stop them breaking. I'm afraid I can't remember exactly what needed to be done.

Allon Whites near Bedford have a good trimmer working for them, so they could also be a good contact for the interior work.

There are a few current and ex owners of Aeromaxs on here and I'm sure someone will be along soon to answer your questions properly.

Glad to hear that it is running well, enjoy it.

David
Aero S4