This is an "acquired taste" and I'm out of practice. In the old days I never used a feeler. I just "roughed in" the dwell "on the starter" then buttoned up the cap and re-checked it "running." After a few times, you get the feel for how much correction to dial in. Also you want it on the "wide" side (28 degrees instead of more toward 30) again because the points "wear in" towards closed.
Also, with points you need a good condenser. Will not start/ run without one
