OR75

the RC Allen 2610 or the UAvionics AV20 or 30 could be a basic / easy to install attitude backup

This look like a homemade bracket. EricJ has a picture of the bracket for the dual mag, and this is what it should look like for 2 mags:

I know it is confusing but actually when folks talk about a Dual Mag it is a single box that has 2 mags inside it driven by 1 shaft if you have 2 mags, each driven by a different shaft, then you actually have 2 Mags (and not a Dual Mag)

Maggie Harness is good should you decide to go that route. Although the lead time can be long. you will need to send your old harness. Are you sure it is the harness ? is it in that bad a shape ? shield in bad shape ?? And what do you mean by shutting both off and voila ? the engine is still running ??

what happened to the timing ? internal timing of the mag ? or timing of the mag to the engine ? don't forget to use the right new teeth washers and torque both nuts correctly (the bottom is a pain to torque)

must be contagious ... having the exact same issue Mag recently overhauled. Checked harness leads and the are all OK. Spark plugs look visually OK and gapped correctly but need to check resistance . Any thought on what the resistance range needs to be ? If that checks, next step is to remove the mag and check the points

I would have thought the JPI would be on the main bus rather the aux maybe a loose connection ? I would worry about it if it happens again

in this new world of GA I had to wait 5 weeks for a part. I took that as an opportunity to change the oil. And since I had plenty of time I let it drain for almost 4 weeks and flushed the oil cooler. Usually, when I change the oil, I let the oil drain a day or 2 I was amazed how much oil dripped in 4 weeks - my guess is like 1/3 quart the bonus is after I ran the engine, the oil was still a light yellow color. Usually it darkens pretty fast with what was left in the sump. if you have a plane sitting in a shop a few weeks and have the oil changed, asked them to drain the oil at the start and let it drain as long as it sits there.

something every pilot owner can tell the significant other is a must have for safety reasons

checked the probes ? easy to switch them and get that out of the way

another option you may keep an eye one: if you get the Hartzel scimitar , then when comes engine overhaul , you can go the IO-390 route and get 10 more HP. should help the climb perf and no loss in cruising speed

McCauleys: C212 or C214 Hartzel scimitar prop 2 blades

Rapco

I installed them about a year ago. they work just fine.

there is a good seminar from Savvy about how typically you sense old engines slowly but surely getting tired (less power, more oil consumption, good old noise engine, ...) while new engines are more prone to catastrophic failure. so, if I was an insurance company maybe new engines should go with a higher premium ! having said that, what I am seeing with my good old engine - an IO-360-A3B6D about 500 hours past TBO (good compression, no metal in the oil) - is that the accessories start getting tired (governor for example) and the appearance is not so great (chipped paint, some rust points, ...) I do fly it regularly about once a week