Hey Ron O!!!!!
I was in kind-of a Peace Corp. thing in Honduras in the late 60's, and one of the locals had a VW Pickup very similar to yours (only with the "rompin-stompin" 36hp motor). He also had an A/C unit hung on the window. It was what I think I've seen as a "Swamp Cooler" in some magazine ads - hung on the passenger side window, looked like a torpedo launcher with a blower in it, a small tank on the top for water, and what looked like a gauze towel inside the tube which had water dripped down it. As you rode along the water on the towel cooled and that cooled the air passing through it into the cab and you got cool(er) air. It wasn't terrific, but it did work and, while I expected the output to be really humid, it didn't seem that way (of course, it was pretty humid outside to begin with - maybe I just couldn't tell the difference!!)
Now.......I wouldn't expect this to be the solution for a Canadian climate (I would expect it to ice up even in the Summer) but you would certainly be the only person riding around your neighborhood with one and the explanations, along with those telling about your Speedster, what it is and all that, might be pretty good.
"Yeah, well, It's supposed to be an Air Conditioning unit, but I only use it for cooling my Molson's"