Palladin (and others);I'd still like the pictures, but if you check here
They have heater valves for 72 and 75 as well as ZX. The bracket is what has changed. The valve is essentially the same. If you do not want to rebuild the one you have, then you could buy one of these and remove the valve from the bracket. It attaches by 2 screws. If you are not mechanically inclined, send them to me. Where are you located?
The good news was that you were correct and it was the gasket. The bad news is that mechanically inclined friend figured bent the control valve (in vise) so that the screw holding the gasket is inop. In other words -- the valve is dead. Reading through your advise above -- it appears that my best road ahead is to purchase the valve for one of the other years (which is best?) adn mount it on the bracket that I have. Sound about right?