hi famous ff...
first off, forget about the heater temp. control - cool to hot. that lever is all mechanical and simply turns a water valve on the heater core to let radiator water flow through the core. there are no electrical circuits connected to that.
remember the basics for internal combustion engines - fuel plus spark. if you have no fuel pump, fuel line and carburator issues that eliminates that issue. now to "spark." it sounds like you have a crossed wire somewhere either at the starter, the ignition switch, the ignition relay by the battery, the coil or at the main wiring harness plug on the firewall. get a good wiring diagram off of FABO or one of the other mopar sites and start tracing wires for the ignition. i had a similar problem with my 340 68 barracuda when i did a final assembly as i wasn't getting any spark. it turned out that i had hooked the wrong "common" wire to the ignition relay beside the battery on the fender well. a place to start is the ignition switch. trace all those wires to the wiring harness and then through the engine area. it is not that hard to do if you get a good wiring diagram. you might also pull the fuse box out from under the dash on the driver's side and look at the top inside of the box for loose and/or burn wires. one last thing. there is one terminal connection that gets burnt on the main plug on the firewall. pull the three plugs out of the firewall connection and examine all the terminals.
i hope this is a start.
oh.. .as to a repair person for this problem ... you will have to either find a retired mechanic over the age of 60 or ask around you local car clubs. if you take this car to a "modern" auto shop for this problem they will look at you like you are from mars....
