Thanks for the warning, but too late. I already removed both bevel rings and so far, cannot get them to fit back on securely. I will probably tap on them with a small rubber mallet to see if I can get the tiny pegs to seat firmly in the holes. If they are not supposed to come off, I guess I could put a drop of Super Glue on them to hold 'em. I tried twisting the trip meter knob counter clockwise, but it did not seem like it wanted to come off, so I left well enough alone. Glass is still perfect. I cleaned it with some anti-fog cleaner for good measure. One thing I noticed when removing the acorn nuts. They were already very loose. Seems they were beginning to back off, with only 1000 miles on the clock. There was something rattling around inside the back cases. Turns out the crimp washers were just lying "inside" the cases. I figure they need to be on the outside of the case where the acorn nuts can be tightened up against them. I ran out of sunlight before I could get everything back together, so I will try to carefully reassemble the wiring and cases. It's a bit more of a job than I thought.
BTW . . . do all of the wires on the back of the instruments come off to allow removal of the instrument frame?