A friend who just purchased a 1977 M-5 210C is wondering what type of paint the factory applied, enamel or acrylic? And what is the best recommendation for wax protectant? Any special concerns with respect to protecting the fabric? Any insight or information would be appreciated.

A call to the factory would give you information on what was originally applied. The Maules I have owned have had two or three cover coats applied though the years. So it is anybody's guess. Touch up painting and/ or recover should be entered in the maintenance logs.

The factory paint on my 1986 MX-7-180 was Sherwin Williams acrylic enamel with a flex agent. It might not be the same for the 1977 M-5-210C though.

Paint in the '70s was Randolph I believe and the fabric was Razorback. Base colour, Daytona White, Maule White, and colors, Maule Rocket Blue(Bahama Blue), Hickory Brown, Bittersweet Orange, Tennessee Red (BD's favorite)(Maule BD Red), Lockhaven Yellow, Lime Green, forgot the Turquoise designations.
Very likely that 1977 M5 if it does no longer have Razorback will have a different paint.
If original fabric there is a good chance it has been overpainted between 1977 and 2021.