S&W didn't start to use model numbers until 1958, so no pre-WWII gun would have a number. Nor were "Victory" models marked that, although the serial numbers begin with "V". Technically, identical M&P revolvers without "V" numbers are not "Victory" models, but they are often called that anyway.
The term "Victory Model" came about when M&P serial numbers went to 999,999, and S&W decided to use a letter prefix. "A" was obvious, but some unknown marketing genius decided on "V for Victory" and the "Victory Model" was born. The term was never used in government contracts or correspondence (where the revolvers were always called the Military and Police or M&P), only in S&W advertising.
Jim