What you are missing grasshopper is seeing what you are looking at. That is not a Sterlingworth straight grip ejector. If you ran the serial number you'd figure out what grade it is.

Here is my guess. It is not an A,B,C,D,F grade. I think it is an HE with a straight grip. Not sure if it is a 3" or just regular chamber gun. Don't be scared but all that fluffy surface rust. Most of that will quickly clean up. So if it sells for 3,500 and cost 2,000 to restore is that a steal or just a gamble.