When the top got replaced soon after I bought the car, I noticed a huge gap between the tonneau and the frame; the upholstery shop told me the frame was tweaked or the joints where extremely worn-out and/or the rivets had to be replaced in order to tightened the frame to its original position, but I need more than diagnostic and I know some vert suffers the same symptoms, so please help.

 

It looks like the flap is flipped up...

John

 

It sounds/looks like the upholstery shop you went to is nothing but a bunch of brainless chimpanzees. The lip of the back portion of the top has lifted from the frame, and it needs to be glued back down with high strength upholstery glue. They do that crap all the time at their shop I would assume, or they would come up with some unbelievable story like what they fed you in order to make you pay more money. Tell them to throw some glue on it to make it sit down better and you'll be fine.

 

I'm sorry to say that I don't think that's the issue. It appears the rear bow is not seated; otherwise you could not see space between the trunk and bow. Maybe the fabric has been placed too tightly?

 

could both BlueZee28 and okfoz elaborate more on your post.
gatorcola that seems logical but how to fix

 

The fabric is held onto the bow by a strong adhesive. It looks like the adhesive isn't working anymore, and the top has pulled away from the metal bow, which makes it look like it is flipped upwards. An upholstery shop should be able to re-glue the top to the bow and you'll be fine. That's what it looks like from the pictures anyways, get some better (closer up) pictures and I'll tell you if my opinion is any different.

 

I have a small gap, mostly in the center by the pin where you could probably stick a ruler into my car between the T-cover and bottom seal.
I have not checked into it because it was not causing a problem.

I think everyone is right about yours, the top could be to tight and pulling up on the bow, and the bottom flap looks to be flipped up, or at least out, it should point down and hide the bow.
They usually get flipped on the side because the compartment the top folds into is not flat and they rub the outside wall on the way down.

Can you go to a diff top shop and get a second opinoin.

For all the problems with these cars I still love mine, it is in the 70's outside today and it is all I can do to keep working and not run outside, drop the top, and cruise the local park.