Any reasonable appraisal will require some pictures as condition is very important in determining value. That being said, based on the serial number and the last patent date, you have an S&W .38 Hand Ejector (Military & Police), Model 1905, Fourth change. That was the same gun that later became the famous "Victory Model" but your gun was made in about 1919-1920, long before WWII.
There were a lot of those guns, a total of 999,999 M&P's to be exact before they went to V1 for the Victory Model, of which 458,296 were the Fourth change. They are not especially valuable and ones in average good condition run $250-300. Note that your gun will not have the positive hammer block safety, so if carried should have an empty chamber under the hammer.
Jim