Once you get a working timing light, try checking the timing with the engine revved up to around 2500 RPM or so and the vacuum advance line disconnected. I'm going to guess the triangle will be somewhere in the vicinity of the pointer, or at least visible in the
timing window somewhere. That indicates the centrifugal spark advance inside the distributor is working. Connecting the vacuum line will add another 10 degrees or so of advance, but only at light-throttle cruise.

Try centering the slot in the distributor hold down bracket, and loosen the pinch clamp that holds the vacuum advance to the distributor housing. You will have plenty of adjustment for timing setting that way. The calibrated slot is called an "Octane selector" and it was used as a quick way to compensate for variations in the anti-knock quality of different fuels half a century ago. Now the gas quality is universally lousy!
LOL!
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
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