Bad Mag (Eisemann magneto) replacement ... Slick Mag?

Easy old mag to have overhauled. Lots of parts up around Maine , New Hampshire. Used in lots of old trucks and farm equipment. There’s a big mag shop down in Missouri or Oklahoma that overhauls Eisemann mags too.
Might look in member directory for Matt Dunlap and his A&P son, lives in Michigan and they know Eisemann mags well. Worth a call.

There is always the DIY way. I started rebuilding Mags At 17, No one showed me how to !. Just go by the BOOK Look for the Mag drop on pre- flight . The hard part is Timing it. Any A&P Should be able to rebuild them.

Thanks to you and Ron

While the engine is running and when I switch to the Right Mag the engine cuts out intermittently... at high RPM it cuts out for a split second and then recovers (and repeats randomly). At low power when switching to the Right Mag it will run a little then cut out completely (and not recover).
The P-lead was checked, ignition switch was cleaned, and seems to be isolated to the mag itself.
I did find the Eisemann manual ... they do look simple and robust ... but as you mentioned my problem will be finding someone to help work on them.

Concur with Ron . Unless you just want to upgrade at about $2000, ,new harness needed! I'm from the old school, Bendix and Eisemann were built more robust. Slick is the "new kid" on the block, in aviation, and reputation has improved over the years, however, as Ron points, no ADs, no 500 inspections, etc with the E, essentially, as in the old days, run them until condition requires maintenance. Again, what's your symptoms? And Fresno probably has any parts needed. Your problem, unless you have the ability, will be finding someone to work on it You may find a manual on Google. It was more common in the old days to adjust/ or replace points at annuals. FWIW

I still am running Eisemann. They are simple, reliable (except when they aren't), and there are no AD's or mandatory overhaul requirements. I have had a couple A&P's recommend swapping them out for something newer but i refuse and they can't give me a good reason other than "they are old". I would suggest having someone take a look at them, it might be something as simple as bad coil or capacitor or worn points (that is about all there is to go wrong).
Why do you say your mag is bad? What are the symptoms?

Discovered a bad mag (right) during run-up on my 415-D with a C-85 yesterday.  My engine logs don't indicate when the mags have been replaced, only refurbished / replaced components 700+ hours ago (and many many years).

Any consensus on how to remedy this? ... I'm leaning towards just replacing both mags now ... if so are Slick Mags the way to go?

Appreciate any advice!!