Hi, I have an 1854 / 58 marked item from Washington Navy Yard I've been painfully trying to ID for several months now. I've researched "Model 1854" without result. As you can see in the photos below it also has "J.A.D" hand stamped on it.....which leads me to believe it may be a significant find. I've read everything I can get my hands on regarding John Dahlgren, WNY, the guns, the Plymouth, gun accessories, etc...... To no avail. If you don't mind please take a look at the attached pictures and tell me your thoughts regarding what this may be? Thanks so much! I do appreciate any help you would be willing give me.