Two Piece Stock spacer

[Rudyard]

Further to my earlier comment here is the jointed stock it was a customer after thought & would been be easier if done from the off set . Rudyard

 

[Tumbledown]

Probably a repair done to replace or fix a busted stock that was damaged because someone forgot to remove a stock pin when taking the gun apart during a restoration.

Nope, these were done as "takedown" guns. This feature isn't common, but there are other examples.