Thank you, and here's an update:
Even though I made the cab in removable sections, I've kept it on the tractor except for the first Summer. The doors lift off their pins easily, and the rest of the cab remains on year-round now. I have a 2-speed fan that can be aimed at the windshield in Winter and me in Summer. The shade from the roof and the tinted glass make it more comfortable than removing the cab in hot weather. It was somewhat of a surprise that it has remained tight and hasn't required any adjustments. Our land isn't very smooth in many places, and it gets bounced around.
The original lighting was changed to LED. It has work lights facing all four directions. Switching controls front / sides / rear independently. There are also bright amber flashers mounted on the on the lips of the roof that face all four directions because I drive about 1-1/2 miles on the road to remove snow at our church.
The plastic strips that were used for the area under the windshield have been replaced with Lexan. The strips became discolored and couldn't be cleaned up.
Minor change to the door latches. The original inside releases were round plastic knobs connected to the latches with short pieces of allthread. With the weatherstripping, the doors need to be closed rather intentionally. Releasing the latch from the inside is done by bumping the knob smartly. The 1/4" allthread stems had a tendency to bend if I didn't pull the door toward me when smacking the knob. I made sleeves for over the short pieces of allthread to stiffen them and now all is well.