Thanks Mike! Here's more...
The windshield frame is very fragile and the way the kit is designed the center of the roof holds it to the rear bulkhead and the doors are hinged off that little center section too. In order the shore up the greenhouse and be able to fill in the seams and allow the doors to operate (and to make it safer for the occupants…), I decided to add a simple roll cage.
The first hoop was made from Plastruct 3/16 tubing to replicate 2.25 inch steel tubing. I found a roll of tape that was the approximate diameter to match the arc of the roof & doors and clamped the tubing to it while heating with a hairdryer.
When it cooled, I spot heated it again with the hairdryer to make it conform to the inside contours. Steel pins locate it to the bulkhead and brass receivers were installed into the tub for the roll bar to slide into.