Eureka used fiberglass roof caps well before 1986. My 85 Eureka Pontiac has a full fiberglass top, rear quarters and back door. My 1982 Eureka Cadillac had fiberglass top shell,, back door, and I think the quarters were also but cant remember for sure. As for the trailing axle on the FWDs, they were not that great, Ive heard of alot of them cracking and needing welded or replaced. They did not use the 6CZ90 commercial body that Superior and S&S used. Dont get me wrong, I love Toms Eurekas.
I'm not saying the the Trailing arms and beam wasn't without problems they were ( my rear axle cracked but was repaired within an hour ) no big deal
What I meant was, what Tom did by coming up with that idea he was able to have a full casket area instead of having the "bottleneck" between the rear wheelhouses.