The blowers on the trunk units were normally off the shelf electric motors that fit other cars of the day. The ones I saw were just 12V electric motors like you might find in a Ford or mid-sized GM product of the 60's.

If you were looking for replacements today the problem would be knowing which car they were sourced from. I think the best way to ever find them would be to just post a photo, say what they are and, and ask if anyone knows if they came from a Ford Falcon or a Chevy Malibu?

All the after market A/C units used off the shelf parts. The hard parts to find are the knobs, vents and cases since these were normally the only parts unique to each different brand.