Welcome to the forums from the Wiregrass! If you measure the barrel from the front of the cylinder to the muzzle, it should measure 6" which is a standard barrel length. A review of known ship dates for the .38 M&P indicates your gun shipped in late 1951 or early '52. Today, we would call this model a "pre-model 10" because it has the engineering design that existed when the model numbers started in 1957. The grips appear to be Jay Scott faux jigged bone. If you take them off, the name and model stamp of the grips should be on the wooden backing plate. If you want to replace them with period correct grips, look for sharp shouldered magnas with blue or black medallion washers.
