A multimeter is useful when timing when the points will open when your using a timing tool, but here you’re just setting the gap. You just need to be on the high part of the cam.
If you have spark, and assuming there isn’t some other issue, it’s possible that you need to replace the crankshaft seals.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.
