deseversky

Third from left is Col. Francis S. Gabreski, the highest scoring ace in the European Theater of WWII. His score of 28 kills were all achieved while flying the Republic P-47 Thunderbolt with the 56th Fighter Group.

Third from the right side of the frame, and next to Gabby Gabreski, is Alexander de Seversky, aviator, aviation visionary, and founder of Seversky Aircraft Corporation (forerunner of Republic Aviation). See: en.wikipedia.org/wiki/Alexander_P._de_Seversky

You have tagged it correctly.
This is not a P-35 but the Seversky company's first built aircraft the SEV-3.
It was built by Edo Aircraft and although undated my feeling has always been it was taken more or less after completion, ie ca mid 1933. First flight was in June that year.
I don't believe it ever became NX registered. It most likely stayed as X2106 until sold to Mexico.
Stig
PS: Need to correct my statement it stayed as X2106 all its life.
Found a photo showing it as NR2106 meaning it had acquired a
restricted CofA and was allowed to fly outside the US borders.

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The gentleman second from the left side of the frame (and to Bud Gillies' right) is "Russian-American aviation pioneer, inventor, and influential advocate of strategic air power" Alexander de Seversky. See: en.wikipedia.org/wiki/Alexander_P._de_Seversky This photo was likely taken at the Hicksville Aviation County Club on Long Island.