Doing a little poking around the old interwebs, found a few tid bits but not a whole lot.
Pug was manufactured by Bruce Manufacturing Corporation in Minneapolis, Minnesota. At some point Jacobsen bought Pug and made these utility vehicles in their name.
While the Pug in this service/parts manual looks a little different than yours, it had head lights etc., I attach the PDF just in case there are similarities to your version, and it might be useful in some way.
Also a sales brochure PDF.
Good luck, take good care of it, that one is pretty rare.