the problem with the roof is the mechanism cable thats clipped into plastic lugs in the frame

if they snap off the cables won't move the mechanism, only the cable

make sure they are all in correctly before you do anything else

also, if you can't remove the screws that hold the glass in place it's going to be another hurdle to cross

the glass though was the same size for all cars of that era, so you can fit different bits from other fords to replace yours, i put on it from a granada even though the mechanism was different, and the escorts glass fitted too