Thank you for the suggestion. I'll check it out.

You referred to ignitor, I'm guessing that you mean ignition module.  I don't know how to test them, its been my experience that either they work or they don't, so it may be that the ignition module has given up the ghost.  If that's the problem, when you replace the ignition module,  a respected poster on another forum from the UK suggests (strongly) to use a 1.5ohm coil rather than the stock .9ohm coil with the 65D distributor.  Says that he has used that setup for years with no problems on an unballasted ignition system.  Have a look at 'the mini forum' and search for a post titled "What coil for electronic distributors (65dM4)".  He explains his reasoning in terms that even I can understand.  Let us know. 

Thanks for the reply.  This isn't a Petronix, it's a Lucas. I know about the Petronix unit failing after leaving the ignition on. Wondering if the Lucas is similar.

I cannot help much with the distributor, but if you are trying to post pictures AND, given that you use a desktop or laptop, it is very easy.
Just click on the green button on the left side of the message reply,

Is the Ignitor the first model Pertronix made? If you leave the ignition on for more than a few minutes, maybe 2 or 3, without turning the motor over with this model it will burn out.

I have a Lucas 65DM4 on a 79' pickup. Just purchased the vehicle, and discovered one of the distributor cap screw holes was stripped. I used a small heli-coil to repair it, but have now lost spark. Grounding the coil yields spark, so it seems everything is okay up to that point. Is there a way to check the igniter on the distributor? As always, thank you in advance.
PS: can someone help with posting pictures. Can't seem to figure that out.