The Mossberg Model 151-K was made for two years only: 1950 and 1951.
Check the Blue Book of Gun Values
No published sn data.I can say that the Mossberg model 151 semi-auto .22cal rifle was made from 1950-1951 if it is the model 151K.The model 151M was made from 1946-1947.The model 151M(a),151m(b),and 151(c) were made from 1947-1958 and were close to the model 151M with minor changes in the buttplate,and sights.
havlinsales.com is the place I go for anything Mossberg. Vic Havlin and his wife Cheryl sell parts for, and repair Mossbergs, and run the Mossberg Collectors Assoc. Very nice folks to deal with.
This semi-auto rifle was made between 1946-1951.
47-58
model 151 k with scope
Depending on condition, between $100 and $200.
Since these rifles were made prior to the 1968 Gun Control Act, they do not have serial numbers, so cannot be dated to a single year. However, the Mossberg 151K was only made for 2 years- 1950 and 1951. It will be one or the other.
Mossberg
You will have to contact Mossberg
If it is a Mossberg, it was made by Mossberg. They did make guns for a number of "store brands".