DannyH was lucky enough to be able to salvage his original ensolite.
I have replaced the "bad" insulation and wall covering on a few projects using "Reflectix" insulation (essentially silver-backed bubble-wrap, approx 1/4" thick—available at Lowes, Home Depot, etc.) and heavy duty upholstery fabric or automotive headliner material.
The Reflectix is exactly what Scamp
uses in their current production models, though they use "rat fur" (hides a multitude of production flaws) as a top layer.