To help you with #1 If your deck has no mounting holes,, possibly it has been replaced and never had the trim installed,, Heres pics of the holes and locations off of mine. All the holes on the lid are in the center of the lip and are 1/4" in dia. From left to right they are located at the following intervals,,, 1/2", 9-1/4", 18-1/4", 26-3/4", 28-3/4", 451/4" and 54" also here is a pic of the clips that held mine in. the oval spring type was on the qtr trim and the nylon "H" shaped were on the lid. They are a compression type that expand when the center pin is pushed in. Last but not least a ? for me,, would anyone try and repair the rusted area in the corner? or replace the entire lid.
Thanks, Doug