I have inherited an older model S&W 38 special with a 3" bbl that I was told was a 38/44 Heavy Duty. However, I'm not quite sure that is correct. The SN on this gun is S922057 on the butt of the handle. Inside, forward of the cyliner latch. there is a small 3 followed by a large #1 with 94900 stamped underneath. What makes me doubt the 38/44 HD is the fact that the cylinder rod does not have the wrap around housing clearly visible on the pictures I've seen of the HD. Any help?