Another piece of trivia. My grandfather's company in the 1970s was Structural Glass. They were the leaders in fibreglass at that time and created the prototypes for the septic tank. Ray Olecko who is publicly credited for inventing the Boler
was an employee there in the late 60s early 70s. The Boler
concept came about during his time at the company as I have understood it from employees who are still around. I can't say 100% if any of the early prototypes were made there but that was what family members recall having been discussed. Ray left the company and since the trailer development wasn't something that my grandfather and his partner were interested in, he got partners and developed it on his own. We have always considered this connection with the Boler trailer fondly. Unfortunately the original owners of the company are all deceased.
My mom and family remember all of the funky creations that came about in fibreglass. Luckily for us we got to try a lot of their creations including boats, portable saunas etc all made from fibreglass. One of my uncles designed his own pop up trailer and made it at the Structural Glass plant in Winnipeg too. My grandfather's partner and family all died in a plane crash, and my grandfather continued building the company until he retired in 1981.
Apparently there were other fibreglass trailers made I believe at Monarch Fibreglass in Winnipeg in the 70s and 80s. There are still people around who worked there. The plant was at the west end of the city on Portage Avenue.