Without a letter in front of the SN? With no letter, your M&P shipped ca. mid-1922. With a V prefix, ca. 9/1943. With a C prefix, ca. mid-1957
That it would be without a prefix. Also, it may or may not have a "Made in USA" stamp on the right side of the frame. That started in May 1922.
There should also be the same SN stamped on the bottom of the barrel and the rear face of the cylinder. Original wood grips would have no medallions
I will not have the gun for about another week, however, I was told that it was all numbers matching.
It does have "Made IN USA" stamped on the right side, as a mater of fact it was stamped very lightly and then stamped a second time much heaver about a 1/4" to the right.
The wood grips do not have medallions. If they are original should they have the serial number written on the inside of the grip?