I have a boat of the same year and model with a custom cherry cabinet similar to the one you picture, just bit larger. It extends forward of the in-floor filter grate. The carpenter who built the cabinet for Previous Owner cut the cabin sole over the AC unit "tub", thus allowing easier extraction of AC unit, exiting straight upwards. You are in a tight spot, not having any easy way to get yours out. I have photos to share of mine if interested.
