OK, here is my idea... now take in account, my hubby is a machinist, so we have tools around here that most ppl probably do not.

Use the screen top you have, cut the edge off from it that goes against the tank.. so it will move freely.. long side, short side..whatever.

Get small hinges (2-3) , use the glue you can get in auto stores... grr, cant think of the name.... it is 2 part stuff (locktite (sp) brand)..... plus there is some you use to glue your mirror to your window..maybe that would work.

Ok, maybe I should have gotten my hubby in on this.....i usually give a basic idea and he improves upon it to make it happen.