The "2" stamp on the hanger lug denotes the "second" barrel set and was the typical stamp used to distinguish between each set (and was an absolute necessity if this second set has its own foreiron). As to the "reinforcing" lug, the first question you should ask is, does the owner have a Cody letter providing original shipping information? If so, does the letter show the gun as originally having been shipped with an extra barrel? In this case, I suspect the extra barrel was ordered at a much later date, otherwise I assume you would be showing us photos of two pre-13 barrel sets with the reinforcing lug feature. As to the reinforcing lug itself, you will note the photo below showing a different version of that same lug on a Specialty, and note also it has an odd "T" stamp; which I, and the owner, feel is most likely a factory code stamp for a gun with the "trap package" as this gun is set up for that purpose (and today I noted in the Houchins book that such a stamp was occassionally used for that purpose, but inconsistently). As FYI I have seen that same "solid" reinforcing lug on other examples, so refer to the type in the above photo as the "skeletonized" version. As to the different steel type stamps, these stamps were placed on raw tubes prior to the assembly and finishing process, so I suspect one of two things happened; either it was a mistake and not noted prior to the point it could be corrected, or perhaps they represent a special customer order (and if indeed this set was added long after original shipment, these barrels do represent a special order). I would also add that, if this mistake was noted by the inspector and rejected prior to shipment, I suspect the shooter who purchased this barrel set received an attractive discount. Whatever the reasons, they do make for interesting disussion.