I calculated the surface area and came up with about 250 square feet. A quart covers 500 or so square feet, maybe a little more. 4 coats is 2 quarts, and add in a fudge factor and I’d say three quarts should about do it. Your mileage may vary based on application technique, waste, and if there is more stuff you want to varnish like the galley.
I did my calls based on assuming the TD is a rectangular solid 8′ x 5′ x 4′. Added in a 3′ x 5′ surface for the bulkhead and a 5′ x 5′ surface for the inside of the galley hatch. I did not include the floor board. Thus (8*5)+((8*4)*2)+((5*4)*2)+(5*5)+(3*5). It’s rough and probably 10% or 15% on the high side, but is much easier than attempting to estimate the area of the conic sections!