Seems to me that the choice of location for most cars from the 30's is limited and may depend on what brand of AC unit you have. Most go on the right side of the firewall. Pictures from other builds of a car like mine revealed a couple of installations with very poor serviceability. I had to cut a hole in my firewall to access one of the hoses on my Vintage air "universal" AC unit, so I made a polished aluminum cover plate to cover the hole. It beats removing a console and dashboard, if there's ever a need to change the hose.

Page 22 of my build log shows some of the choices I made. I agree with paying the bucks for the stainless lines, at least if they show much. I getting ready to change some of mine over to stainless.

'37 Oze build