Aftermarket Sunroof

I love factory sunroof cars, but aftermarket ones, not so much.
How much work is it to plug the hole?
I would never try it myself, especially since this is a non-vinyl top car, but just trying to decide if it is even doable or if I want to go see this car in-person.

I think it is a big reduction in value on a 70 e-body.
What say you?

The pureists would say you should replace the roof skin. The rest would say find a donor and start cutting a patch panel, weld it in and Bondo.

Which is right depends on the inherent value of the car and what you intend to do with it

A roof skin is one thing, but if any of the roof structure/bracing was cut for the install then you'll be looking for a donor roof. With the value of almost any E body having gone through the roof (no pun intended), if the rest of the car is decent it could be worthwhile. For the same reason, though; a donor shell could cost you almost as much as a basic A body driver... but deals are out there.
All depends on your ability and where you're going with it.

How rare is the car? It shouldn't be too hard to find a Challenger donor car with a decent roof section, but, a Barracuda will be a bit tougher.. If you go with a full roof cut at the factory seams, it's going to be expensive to get done. Just a patch panel welded in around the sunroof opening would be half that or less depending on inner braces and degree of body work finish. Hard to say what the actual cost would be. Every shop has their own prices and degree of expertise. If you can't live with the existing sunroof, I'd locate a donor roof and get some estimates before buying the car.