So unless they've changed their style of production, I'm guessing it's not them.
When we visited Accubuilt/Superior/S&S at the M-M meet in 2009, they used fiberglas panels built by an outside supplier. But they had individual parts (back, sides, roof, etc.) and attached them to a metal frame. So unless they've changed their style of production, I'm guessing it's not them.
my question is changing over to a fiberglass body corrected any rust issue's in certain problem area's and maybe made it lighter?
As Ed said, no! You have to remember the use of fiberglass in these cars is nothing new. I know for a fact Superior was using fiberglass panels in 1960, prolly earlier. Also, Eureka was using complete fiberglass rear shells (top, sides, rear quarters, loading door) in the mid 80s. The fiberglass cars seem to run around 5,000 LBS.
What that guard told Jim has some truth in it. My shop manual is very specific. It says to never use a finger type/frame lift when lifting a series 75 or commercial chassis. This is in the 1961 Cadillac shop manual. Other years may have other instructions.
Mike