I agree.....
I think these might slightly go up in value simply because of supply / demand.... but I don't think they will command big money one day as they just don't have the sexy appeal of the RT embossed machines.
These Square Top machines provide people who are not crazy about machines, an opportunity to have a beer / pop machine in the mancave , and maybe even detail it as their fav. sports team, beer brand, Harley Davidson etc.....
I think money can be made by restorers with these, because of work involved etc.... but I cant see a great return on investment if people started to stockpile these up..... unless they buy them from old ladies at garage sales for 50 bucks I guess