Knee knocker in 73+ abody?

I'm looking at the same options.
These guys were at Syracuse Nationals this year, I checked out their website and there are possibly too many options with multiple selections to make for each.

I'll probably go this route as well, just need to determine which one:

Oldairproducts.com
Check out A/C for antique cars | Coldmaster | USA

These guys seem to be the cheapest, and let's be honest all this crap is made in China so why pay more.