I have a 1976 Lancer 25 with 4 fixed plexiglass ports. From the deck side, they appear to be simply glued against the underside of the cabin. The boat's prior owner apparently tried to fix a couple of leaks by running a bead of silicone around the outside of a couple of the ports and you can guess how nice that looks. Unfortunately, the headliner in the cabin is rounded right up to the edge of the port. Without removing the headliner, I cannot tell how the plexiglass is affixed. Anybody know? I am contemplating removing the entire headliner (it has a few tears in it) anyway, but then I have to find someone who would be willing to upholster my entire cabin...and I can only guess what that might cost. Any suggestions or advice would be welcome. Thanks in advance. John