I guess I have followed the practice mentioned by others... if they are
Bendix, check the points & clean out at 500 hours while doing the
impulse coupling check. Follow SB599X

The old slicks with the plastic cam needed attention every couple
hundred hours. Newer ones seem to last like the bendixs.

So I find points with a little wear at 500 hrs, but OK; at 1000 hours,
usually replace them and they are good to go till tbo.

On the slicks, the dust from arcing in the towers will often short
out the distributor caps. So it's a good idea to clean the distributor
caps while they are out.

Sure there are two. What do you do when you fail a mag check
in Bum---- Nebraska on a Sunday?

Bill Hale A&P