I have been stirring over this one for awhile. I believe it is a 1956 Sherwood 14k solid yellow gold. The case is marked L4, the movement is marked L6. Not unusual to have mismatched date codes, i do however seem the the other way around most often. a later case with a year or two movement. in any event, i do not believe this is a replacement movement. The watch is so clean and from what i can see unpolished. The edges are crisp not rounded from polishing, The case back is free of any watchmakers service marks. The bracelet that is near spotless. Even in the crevices of the expansion joints, its super clean. The crystal and black dial are stunning to the point of having a mirror like quality. Case back and Bezel (with crystal) weigh 11.19g. Case Dia excluding crown is 1-5/16" (33.3mm) , lug to lug 39.1mm and lug width being 11/16 or (17.5mm).
This watch is very similar to the President of the time, but in adverts all the President models are listed as 10k Yellow Gold Filled and 17j. The two adverts i have found that detail the Sherwood list it as 14k solid yellow and 21j which this watch is. Both adverts show it as with white dials (perhaps due to it being artistically easier to show detail on white dial rather than a big blob of black ??) and no variants for a black dial, but i do believe this is an original dial. (But i could be wrong). Also, the adverts show a lether strap, this one currently wears a Finesse USA semi-expandable which may not be original but i believe to be period correct and stylistically matches the watch perfectly.