Interestingly, the term "Victory Model" was never official, even though S&W did use it in advertising. All correspondence with the government used the terms "Military and Police" or "M&P" revolver.
The Victory model came about in an odd way. In 1939, the British contracted with S&W to make 9mm carbines, advancing S&W a million dollars. The British were apparently thinking "STEN" while S&W was thinking, well, S&W. The product was a beautifully made, perfectly machined, semi-auto light rifle, designed to fire U.S. 9mm. When the British wanted to increase the power of the cartridge to their desired levels, the guns wouldn't hack it. But S&W had spend $870k of the advance and couldn't afford to pay it back. So they agreed to give the British revolvers, their regular M&P model in the standard British .380 caliber (sometimes called .38/200, even though the FMJ round used in WWII did not have a 200 grain bullet). Collectors call the M&P of that date the .38 Hand Ejector Military and Police Model 1905, Fourth Change.
So S&W cranked up and started production. Their serial numbers for the M&P were already around 700,000 and the contract production soon approached one million. But S&W's numbering machine could only handle 6 digits, so they decided to add a prefix, probably "A" which would be stamped on all the guns as a separate step from the serial numbering. But some advertising genius thought of using "V" for Victory. At that time the "V" and the phrase "V for Victory" were seen everywhere, so there was nothing odd in using the "V".
Of course, the U.S. saw the benefit of having large numbers of revolvers to supplement the Model 1911A1 auto pistol that was standard issue, and also ordered S&W M&P revolvers, but in .38 Special, a caliber that was in the U.S. military supply chain, where .38 S&W was not. So S&W produced some 850,000 wartime M&P models with the "V" in addition to some 200,000 made earlier without the "V". Technically, only the "V" marked ones are Victory Models, but collectors usually lump all the war contract guns under that name.
Jim
