After installing the hardtop in my 1971 280SL this past fall, I noticed that the latch on the right side of the windshield does not stay tight for long. This results in some rattling of the top while driving. When re-tightening with the locking handle, it quickly becomes loose again. Are there bushings of some sort inside the front attachment posts on the hardtop that may have weakened, thus causing this problem? If so, are they available and will they cure this problem? Please advise, and thanks from suburban Philadelphia!