No, I have a 50 gallon newer tank under 90% of the starboard settee and a 40 gallon original tank under the V birth. When I was first thinking of relocating the batteries the goal was to help balance out the boat with the 50 gallon tank full. Now that I've decided to go with lithium, I'm not getting as much weight to offset the 50 gallon tank. One nice benefit is the aft section of the port settee is a lot easier to access then the outboard section.
You might be able to add a starting battery to the compartment under the nav desk seat. That would free up a little room in the standard battery compartment. If you're looking for more room, my boat has a large unused space on the port side of the V birth just forward of the shower bulkhead. I would have to cut an access hole to get around the drawers to use it, but it's an easier spot to route battery cables to. I considered this spot for the holding tank when I replaced it, but ultimately decided to keep it where it was.
I used Total Boat Bilge paint. I have enough left over that I will use it for a few other lockers, but I don't recommend it. It's really difficult to put on thin enough to dry quickly. ultimately it will dry hard and durable, but that takes a long time where it ends up a little thick.
