folding windscreen--hinges broken
 

The folding windscreen for my 560SL no longer stays put at the right angle in the open position; there's a detent where there should be a hard stop, but it opens beyond that under wind or hand pressure until it's no longer screening wind. As far as I can see, there's not a way to take the hinges apart and see if they're fixable. Anyone else had this happen, and anyone out there with any clues?
TIA--