Something is not right here.
S984704 would be from March 1948. BUT there are features shown that would disavow that date.
This revolver still has a threaded hammer pivot stud and the barrel shaped extractor rod knob. Both of those were long gone by that serial number.
Here's the clincher: The S is in the wrong place relative to the serial number. I have never seen a postwar unit with the S and the END of the serial number. The serial number is placed in the location that would correspond to a prewar gun and the S is at the wrong end. The sideplate is marked with the small S in the upper left-hand corner, where it belongs.
Here's what I think is going on: The actual serial number is 984704, putting production in early 1942. Sometime after December 1944, the unit was upgraded to have the sliding hammer block safety, got a new side plate, and was stamped with the S on the butt, where it would go if the unit was new production. Sometime after that, it was refinished in nickel, which also obliterated the evidence of the swivel hole on the butt.
It would be interesting to know what serial number is stamped on the barrel flat.
BigEd84 - would you post a photo of the underside of the barrel with the cylinder swung out? That would be helpful.
Edit: If I am correct about this gun (and I believe I am), it is the lowest serial number on a Navy gun returned for the upgrade that I have found so far. The reason it isn't marked SV is because it never had the V. It was produced and shipped to the Navy before the V prefix started in April 1942.
