It's a bit of a myth. Only way you can damage the pick up coil, is if you leave the ignition switched fully on while messing with car and distributor cam happens to be stopped in one of a few wrong places. If you disconnect the power line to the Pertronix when messing with car, then there is no problem. A quick disconnect of some type might help. On most cars, power only gets to Pertronix when ignition switch is switched to fully on position (so Ok to run radio etc with switch at first position)

I have had my Pertronix I for quite a few years with no problems. Apparently the more expensive Pertronix II has burn out protection, but does not like the Euro solid core wires found in our cars. Most MBs of that vintage have them.

I know nothing of the 123Ignition units in the link below. They don't make them for my V-8. But they do look interesting and you get a whole new distributor (for a price!)

Mercedes Ignition from123IgnitionUSA = Perfect Timing Every Time

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5