Darold, by your serial number it dates it to 1900. The "00" would be the grade and starting in 1899 it was offered with Armour (spelled Armor now) Steel barrels. The other numbers are patent date numbers and if you go to the L.C. Smith Collectors Association and click on it will open to different topics click on FAQs and also go to patent dates. You also stated "raised rib", most ribs were concave, but anything is possible,. If it was an "0" grade the barrels if steel would be London Steel, not Armour. Hope you will join the L.C.S.C.A.