Graham, Exactly which .38 DA model do you have ? Is it hammerless or has a visible hammer? There are about 3 or 4 types of cylinder stops depending on serial number, date of manufacture and particular model of S&W the gun is. Where did you get that Part number? Can you post a picture of the part you need (from a S&W parts diagram for your model) That number doesn't match any of the circa 1885 gun parts manual's numbers for a cylinder stop. The style that breaks most often is a long piece about 1 1/4 in. with a curve in the middle. If your style that type, and you have all the pieces, a careful welder can restore it, as it is not spring steel but is operated by the cylinder stop spring. If it is the spring that is broken, that's a whole different ball game. Tell us what you have & I'll tell you how I fix them. Ed.