Thanks very much Rocky and Matthias.Most helpful.
I guess if I purchase an adjustable the two bolt type pointer that has some adjustability I can set the piston position at TDC and lock the pointer onto the zero position on the harmonic balance markings. That will give me the front location accurately .
Then I should be able to swing the motor each way and using the harmonic balancer marks and pop the relative positions from the flywheel onto the bell housing for the other positions for those quick rear checks.
The machined graduations on the flywheel may have to wait a little while ....!
Great idea on the 12v rear socket. I will add it to the slowly diminishing list !