Okay so we are in agreement that the fiberglass are a bit better.
Now, lets get our thinking caps on and post information on the manufacturer.
I'm sure, just the same as I've contributed to the GMA Cover Corp, manufacturer of cab tops, and cargo covers, that there is someone who knows where these fiberglass troop seats are made, or who makes them.
OpenDNS
For a new set I would absolutely call the manufacturer and have them freght shipped to my house.
If anyone has a set, including a head rack, please go and look them over carefully and see if there is a CAGE # anywhere. They will usually have Five alpha/numeric characters or if they are older, like a a manufacturer from WWII, five digits that signify the manufacturer.