It only took 4 years of procrastination but I finally have my original heater installed and working. Thanks to fellow member Chistech who refurbished and re-chromed it, she's throwing off terrific heat. It was quite a physical effort though, wiring, mounting it while squeezing myself under the dash. I added 2 shut-offs in case things went south. But no leaks and it did drop the engine temp down immediately when turned on. Good for dumping excess heat on hot summer days, and parades maybe. I know, I need a correct hose clamp and my plumbing is a little excessive....
Meanwhile, it's there if I need it to warm the toes. Got 130 degrees with the IR gun on the heater. (Repro knob from the FS)