Well, another rookie mistake set me back a couple days. A friend had some polyester resin available which I used to glass polystyrene foam insulation panels to the underside of the deck panel and hatch of the forward fish box. The foam basically turned into soup so I had to redo the entire thing with old reliable epoxy. Dumbass. Here's attempt #2 which was a success.
Other progress since last post - wired new macerator pump for fish box, installed Garmin GSD10 fuel sensor, new senders on both tanks, lots of wiring clean up, re-patched/glassed muffler, installed new intake hose and through hull drain out the stern for livewell. Drain system is CG approved reinforced hose to bronze through hull with a flange and flapper valve similar to the exhaust port - safe, clean, and hopefully it works! Will take some pics tonight.
Tonight's punch list on the fish box insulation project - install thru hull drain, plumb to new macerator pump, apply Interlux epoxy primecoat.