I believe this to be a shore party medical chest based on information i found on a WWII collectors forum:
www.med-dept.com/forum/viewtopic.php
Here is a link to more pictures:
paulcardone.photoshelter.com/gallery/WWII-Medical-Chest/G0000XQpcciFrJWI
It seems to be fairly rare, i have not seen anything else similar on the web other than the example above. It is real heavy duty, weighs about 50 lbs, very sturdy. Can be laid down and used as a chest or stood on one end as a cabinet. Heavy cloth straps on either end. Strong, working claps. I assume the knob is an addition as it would get in the way of stacking but it is very old, the screw seems to be as old as the rest of the hardware on the chest. The paint seems to be original but I am not sure. I am told the gray paint may signify it was used in the Navy. Any further information and an idea of value would be much appreciated.