Jim covered the matter pretty thoroughly so I'll just add an additional commentary that might not brighten your day. There have been all manner of folks who got into the glass body business in the hot rod hayday a few years back. Not all them knew, and some didn't care, how well the body and it's components were fabricated. One common issue was the hinges were made of material too light duty for the job. When that door is open there's considerable weight leveraged out there, the hinges bend either in the strap or the box that they usually pivoted in (mounted inside behind the opening framing). Sometimes the fiberglass or the bond to it holding the metal component will be failing, again because it wasn't sturdy enough. Hopefully it's not this more dire scenario, but fore warned is fore armed.