Not as lucking as you might think. Those tops are in Decatur Indiana, just north of where I am located, and the guy who has them for sale is short all the seals for the windows, windshield header, rear window, and most of the attaching hardware. Without that it would be difficult at the least to get one installed and have it not leak or fit correctly.
My top is in storage right now. Plan on getting it out soon. I did purchase mine from the Decatur, IN location. Reviewed the pictures I posted a year or so ago and here is what I think...There is no seal on the top where it mates to the windshield surround. The existing factory seal is used. If the two locating mounting pins are missing, they would be easy to fabricate. The front latch is nothing more than a J-hook and nut. Would need to make a plastic or thin aluminum plate to cover the hole. The side window seals (driver/passenger) will be the hardest things to come up with. The seals provided by Smoothline for their Solstice tops will not work. I think a guy on the forum was trying to make a set of seals from a spare soft top work. Never heard how that came out. Where the top meets the sheet metal just behind the doors and before the trunk lid will require a seal but that does not look to difficult to figure out. If the rear glass (hatch) is missing, a good plexiglass man could mold one. I don't do it but at the Air Force Museum Restoration shop where I volunteer, they are always forming new plexiglass for the old aircraft canopies when needed. Hinges for the back window do not look to hard to copy. The main mounting plate for the rear could be fabricated without too much trouble. Locking latch for the rear hatch could possibly be taken from a pickup shell. The only piece that would be somewhat hard to make would be the plastic cover that mounts just inside the hatch. The headliner is kind of a joke anyway. Be better to have an auto upholstery shop do that job. Rear side windows are the same as the hatch. Could have someone form them up. Gotta be people available who do that sort of thing due to all the custom car and hotrod shops around. Side rear windows are glued in, by the way.
In other words, I would not be totally afraid of purchasing a top as is but it might get a bit expensive to accomplish the final product. If anybody does this, I would be glad to provide templates, measurements, etc.
Look up my posting "EDAG hardtop Purchase...", page two for pictures of what I am referring to.
The only time mine has leaked is when I took the car thru the hi-pressure car wash. Leaked profusely around the side window seals, mainly at the bottom rear corner. The top side windows and hatch produced no leaks. Have had the car in a couple of good downpours while on the road with no leaks at all.