Youve got to be smarter than me to post photos here; but you have found the original factory grade marking, "OOE". The Grade OO gun was the lowest grade hammerless Smith gun produced from its introduction in the mid-1890's until discontinued in 1913. The "E" suffix stamp indicates your gun was originally manufactured with the very desireable $25 auto-ejector option. Since you now know your gun is Pre-13, you can date shipment from the serial number records; but that's about all I can tell you with the information provided. If you learn how to post photos, please do as some of these early guns were up-graded employee guns; not that yours is, but if it is the engraving style will be consistent with that seen on higher grade guns from the period.