Here is another interesting one I can't quite figure out. It most closely resembles a Watertite "F", but the lugs are slightly different (lug to case transition) from ads, as are the indices and seconds/minutes track. I find only one example of this configuration anyplace, and it's on Lisa's site as seen here. Hers is s/n 315152 ( a difference of 184 ) and also a 1951. I first wondered if this was a re-dial, but the existence of another that is identical and so close in s/n suggests otherwise. All identifying markings are on the inside of case back as seen.
Case is chrome plated, 17J L1 movement. Face with lume numbers and hands with red second hand and gold indices, as described in 1951 ads for the "F".