I'm not sure exactly what the letters "MT" mean (other than perhaps Model 12), but the numbers themselves indicate the gun was manufactured in 1912. That makes sense because they were simply numbered from "1" on up starting the the year 1912; therefore they would be early examples of the model. If the slide handle is approximately five inches long and has 13 circle grooves in it, you know you have a model produced before 1914.
Your question has used the serial number of your Winchester,not the Model number.Please include a description of your Winchester along with the model number,and the serial number to get a answer about your Winchester.
If you are asking when it was produced?Then your Winchester model 61 was made by Winchester in 1953,with the serial number that you provided.
With the serial number that you provided,your winchester model 70 rifle was made by winchester in 1970.
With the serial number that you provided,your winchester model 1894 rifle was made by winchester in 1913.
With the serial number that you provided,your winchester model 12 shotgun was made by winchester in 1927.
Your Winchester model 64 was produced from 1933-1957,and the serial numbers were listed among the model 1894 serial numbers.Your Winchester model 64 was made by Winchester in 1934.
Imposable to answer without you providing a serial number to your Winchester model 12 shotgun.
Model 70 winchester serial number 432523 chambered in 416 rigby
While the Winchester model 190 was serial numbered,Winchester did not keep records of the serial numbers by year of production.I can say that the Winchester model 190 was produced from 1974-1980.
Your Winchester model 1894 rifle was made by winchester in 1971,with the serial number you provided.
your Winchester model 62A serial no.349772 was made in 1956.
your Winchester model 190 was made from 1974-1980.