I am little puzzled why it doesn't work, I've used odd ball coils in the past that didn't even fit that worked, that is why I was thinking magnets.
I also tried flipping the coil over, grounding the coil to the block, filing the top of the posts for good contact.
I took the original coil and sanded off the rust around the mount holes and actually got it to read 5.** on the ohm meter consistently, still nothing. I have never had a problem with magnets, except tecumseh ones that fall off inside the flywheel.
And of course I might have made the wrong decision buying this coil. I see used ones for $15, don't really want to buy one of those either.
Briggs changed coil suppliers a few years back, and the new coils may not look like the old ones. Some even require that the block between the coil mounting studs be ground down to clear the new coil, as well as trim the inside of the blower housing. At least on some of twin cylinder engines.