Hi Lalo --
Your Scott #26A stamp with the extra left frame line is position 70R11i.
FYI -- plate 11 exists in 3 states -- Early, Intermediate, and Late -- but on the Intermediate state of the plate, positions 70, 80, 90, and 100R were entered with misplaced reliefs B through E (versus the normal C through F reliefs). Your stamp is a misplaced B relief thus enabling the state of the plate to be determined with certainty.
You can read more about the guide reliefing method of production that was used for this issue in "The 1851 Issue of United Sates Stamps -- A Sesquicentennial Retrospective" -- published by the United Sates Philatelic Classics Society -- and available for free download on their website. Link is here:
https://www.uspcs.org/wp-content/up...CS_and_B.pdfI am also attaching a reference pair of positions 70-80R11i for comparison to your stamp -- (not my stamps -- but courtesy of a close friend of mine who is an expert on this issue -- the "Central Coast Plater" -- who wished to maintain confidentiality here on SCF

).
Regards // ioagoa
