I installed a glass sunroof in my TCS back around 1975.
It was purchased from Tomco (Washington state) and had 3 positions: closed, tilt (rear up), or removed. ...I made a storage case for it, and it fit in the luggage tray, so it was always with the car if removed.
There was no fiberglass work needed (it clamped in), and never leaked.
It made a HUGE difference in cockpit ventilation during the summer.
I did keep the panel I cut out in case it was ever returned to original.