The past several years I've been manually adjusting the thing and zip tying it place twice a year because I hadn't gotten around to attaching a cable. Gettin cold in the mornings now but hot in the afternoons so nice to have the option to adjust the heat

Anyway, I had a spare heater control cable from a 1952 Pontiac Chieftain (same part as a 1952 Olds Delta 88, it appears - slightly different cable lengths) for an OT project, decided it belonged in my 49 to control my water valve. Really a beautiful looking part.
I had to lengthen the cable and wish I'd taken photos. I cut the crimp sleeve back, removed the old cable and took a universal control cable and attached that to the pull rod (which was a pain because the new cables are positive junk, they don't bend even with heat and they also don't compress so you can't pinch em like the originals. I ended up soldering it to the rod, hope it holds. If not I'll go searching for a better cable).
Then I used my hydraulic crimpers to reattach the main sleeve to the coil spring jacket of the new universal cable.
I did have to open up the choke/throttle hole a bit in the dash for it but otherwise she fits. I like it because it's stainless, it's original period-correct GM and says right on it what it's for. It also has little detents in it so you can (in theory) fine tune the heat and it stays in the notch.
Looks from the photos like I need to rotate it clockwise a bit. Never looks the same when you're starin at it.
Anyway, just thought I'd throw it up there to give interested folks ideas.