I see 2 1/2 and 12-70 which makes me guess that it had the chambers lengthened. It also says 13 and .719 on one barrel and 13/1 and .729 on the other.

Chamber lengthened and then re-proofed?

The gun is listed on line by Cabelas: http:/www.cabelas.com/product/JW-Tolley-BLNE-With-Makers-Case-Krupp-Steel/1117762.uts?Ntk=GunLibrary&searchPath=%2Fcatalog%2Fsearch.cmd%3Fform_state%3DsearchForm%26N%3D0%26Ntk%3DGunLibrary%26Ntt%3D891371%26x%3D20%26y%3D9&Ntt=891371