My panel is home made rather than manufactured but here is how I solved two of the questions posed in this thread.
Rather than screw through the flange to mount the panel I grafted clamps from an electrical Carlon device box to the backside. Tightening the screws draws the clamps up against the coaming and compresses a flange gasket. No caulking used, easy to remove, easy to install.
For the Plexi cover I used two polished aluminum channels, the top one deeper than the bottom like our galley slider tracks. To remove I lift the cover up into the top track as far as it will go, pull the bottom free of the lower track and remove downward. Works great.
