Well, success at last. And yes, the dial was fit just as you said it was. This watch has very close tolerances everywhere. Even the stem needed to be moved a micron or so in order to properly engage the detent.
After taking a break, and sleeping on it, I went back at it this morning. After successful placement of the stem, I grabbed the dial and set her in place. I gently maneuvered the dial around to line up with the “pin”, pushed the dial rim from the opposite side to get it to clear the lip, pressed the area above the pin and she snapped home. I then just made sure that it was equally set all around, installed the minute hand, and away she went. Many thanks for your help, Bob. I’ll be popping in now and again and contributing what I can.
Note: I had purchased special plastic-tipped tweasers for a couple of bucks at Harbor freight that I’d planned to use for handling watch batteries. It came in very handy for grabbing this guilloche dial without much fear of damaging it.