I'm not sure the sight was modified, but the frame looks shortened on both ends. It's possible the sight was altered, or just hangs over the shortened frame a bit.
The engraving does look to be lesser quality than the stocks, but I can't tell if it's done with a pointed punch, or not. Most of the Marlin Ballards and Marlin lever action rifles had some punched or stamped engraving on the borders, but not this style. In general, the borders were stamped by apprentices at sometime before or after the master did the main panels. Border work being punched was repetitive, and above most masters.
I was talking with a close friend Sunday who is the secretary for the Engravers Guild, and he told me on occasion an advanced apprentice did the entire gun, and the mater took credit for the work when it was sent to the factory or customer. I was having him examine my engraved Ballard, to determine if it was Nimschke, an apprentice, or one of the other engravers Marlin used.
If you look at this action, you can see the stamped borders on repetitive designs. The rest is Nimschke engraving.
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