Kevin: I have the same 2 port/stbd lockers on either side of the aft cockpit bench in my E35-3. Never could figure what they were for because of the 1" "rain" hole....Previous owner kept "stuff" in these...and because of the hole in the lid, filled with rain water and could not drain due to the soaked "stuff"! Through out all the soaked stuff, cleared the drains and now ready for the propane tanks for the 2 burner galley stove! I had no idea where to store the tanks! That's quite a distance for the starboard propane hose to the galley..will need to find a longer hose! Great to get things figured out! Thanks for your kind info!
Tip: I also use a Dremel engraver+permanent marker to etch my boat registration number on all things that could "accidentally" fall overboard...poles, life jackets, life ring, buoys, bumpers, etc.. "If lost/stolen; return to "X" Marina for a modest reward". If they show up, one less beer...if found on another boat...knock on the companion way or a "friendly" note.