When I build up a stovebolt engine, I fabricate a pointer and file a TDC reference line on the crankshaft balancer. Then I can use my Innova delay flash timing light to check spark advance and set the initial timing. I've got a Sun distributor tester like the one in the above picture that needs a good rebuild. The xenon flash tubes for the Sun testers are no longer available, so I use the same delay flash timing light to check the advance curve.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!