So you know, the slots in that plate allow you to move it slightly clockwise or counterclockwise to adjust the timing.
With that in mind what I would do at this point is to make a few marks like in the pic...
... remove those two long screws with a slotted screwdriver and see what's on the other side since I've heard nothing that would make me think the coil is bad.
As long as you make accurate marks BEFORE to take it apart then reassemble it exactly like you took it apart you'll have no problems.
If you decide your mechanical aptitude is up for it let's see what you find! If not, just kick back and wait for the coil. If the new coil doesn't fix the problem we can continue to troubleshoot from there... your choice.
Dennis
PS How are you with a multimeter?