advice would be much appreciated.
Try doing these tests:
Cylinder pressure test (aka compression test). The highest cylinder pressure should be within 10% of the lowest cylinder pressure!
All spark plug will be removed.
Ignition system will be disabled (remove power source from ignition coil to prevent damage).
Each cylinder being tested will be cycled at least 3 Xs during each reading. (pressure will be accumulative.... this gives us a more accurate reading)
Cylinder leak-down test. This test will help determine which cylinder is low, and hopefully where the leak is occuring (piston rings vs vavles, etc.)
Vacuum test. Adjust the low speed circuits to obtain the highest idle speed. Idle stop may need to be re-adjusted.
See where the ignition advance is at idle speed. (aka BASE advance or Initial advance)
Q: How were the cam followers adjusted after the cylinder head work was done? If one or two were adjusted too tightly, you may have a burned valve or two by now!
Q: If still using a contact point ignition system, how are you adjusting the dwell angle?