LA Mopar electronic distributor retaining clip

In the car?
Just making sure you're clear on this.
If you want to have 34* maximum, and 12* initial, then set the advance slots for 34-12=22*

Since you don't have the keys, this is probably pretty good guidance.
From [WANTED] - Mallory 29014 Advance Curve kit

14° = .130” or 3.3mm or #30 drill
16° = .149” or #25 drill
18° = .167” or #19 drill
20° = .184” or #13 drill
22° = .202” or #7 drill
24° = .225” or 5.7mm or #1 drill
26° = .240” or 6.1mm or B drill
28° = .260” or 6.6 mm or G drill

Not in the car. On the bench, as measured with a degree wheel. Setting is very fussy. LOL. Very touchy indeed.

And yep. Totally understood. Total, minus initial, equals X. Divide X in half and measure out on degree wheel.