US #11s With Possible Jackson Depot Railroad Cancels - Please Help Identify

I would appreciate help identifying this railroad depot postmark. I have three examples, all on US #11s printed from plate 8, so the period of use would be from May 1856 to October 1857. My research so far indicates Jackson Depot New Hampshire is the most likely candidate, followed by Mason Depot New Hampshire . . . unless I got the state wrong.

The middle cancel sure looks to have N.H.

Comparing all 3, the date and (N.) H. look fixed relative to each other. That's normal and says to me it's a standard type, not one that a poor local printer made up. The lettering in all 3 match each other, so there's only one device here; that's to be expected anyway. Based on symmetry relative to the date and state, JACKSON fits very well, much better than MASON.

Thanks, hy-brasil! It would be nice to see the full postmark, but I don't have any railroad cancel books.

The only book I have on cancels is, U.S. Postal Markings 1851-61. I don't find any RR cancel, 'double ringed circle'. There are some 'oval' but not for New Hampshire.

Having the word "depot" in the town name does not automatically make it a depot cancel or a railroad related cancel. I believe this is a normal postal cancel from a village PO.

Looking at the PO list for New Hampshire on Jim Forte's webpage for towns with the word depot in the name, the only town with "*N DEPOT" is Atkinson Depot, which opened in 1854 and has the right number of letters to be symmetric. The 3rd image also seems to have "SON" before the word depot.

Thanks, John! I think you likely identified it. I'll keep looking for a more complete postmark to confirm.