I installed a 75 240 ignition in my 71 142e but that was just because I was using the engine from the 75 complete with the K-jet injection so I needed the panel that fits at the top of the firewall where the fuel relays mount and it also has the ballast resistor etc mounted on it; also I had to use part of the 75's wiring harness anyway; also I didn't want to mess with pulling the distributor and putting in one of unknown reliability as I had driven home the 75 and knew it ran okay. Just today I got most of the pieces moving in formation and took my project for a quick turn around the culdesac before parking with ends switched in the drive so the neighbor know it finally moved.

Anyway, yes the ignition seems to be working fine but it is somewhat rare. If what you have works well, why mess with success? If you must, search the web: somewhere I read a how to page complete with schematic and information on adding a diode and ballast resistor, apparently assuming you would salvage the distributor and ignition module but not get the wiring. Probably this is likely to be the case. Also remember you are talking about finding a distributor used only one year and that was 27 years ago.

Mel