UPDATE: I spoke with MM tech support and while he was very polite, he was adamant that the 350 finger and the 360 fingers are the same. I told him the manual says differently and even pointed him to the page and diagram, but he refused to even consider it. So, he refused to answer my questions about how to properly drill and out and replace the rivets. He said I should just replace the finger.
In addition to that, he said that before replacing the finger, I should check four other other things. Belt timing, millivolts on thermocouple, gas pressure, and amp draw on the blower motors.
The only thing I haven’t already checked is the amp draw on the blower motors, but if that is the problem, that’s worse than the fingers. So, let’s hope that the finger(s) is it.