I picked up a Hampden wrist watch from an online auction and the watch arrived yesterday. I plugged the serial number into the pocketwatchdatabase.com database, as well as the Hampden Lookup Table by Henry Burgell. They both identified my watch as a 17 jewel Hampden Grade:The Four Hundred, Model: 4, made in 1911. The pocketwatchdatabase.com response also had a picture of, I assume, the Model 4 movement. My movement is exactly opposite their pictured movement. It is its mirror image. How can oppositely configured movements be considered the same model? Any insights are greatly appreciated.