I just got a 1979 Sunline 8 SDR truck camper which was stored inside for 26 years.It needs a new skylight over the cab bunk.The whole thing is screwed in with a frame,screen and crank to open up for air.I think it best to replace entire piece.Any ideas where to get something that would fit in?All it really needs is the outside plastic which is cracked but it is rivited to the base.Thank you