Blowing up the photo I can see a possible reg # 6677 in top centre of the dashboard
The USAAF had aB17 44-6677 but its not that
and there was an N-6677 which was apparently a mid -70's BOWLING BENSEN GYROCOPTER Rotorcraft (?*I|?) and it doesn't look like that.
some of the military sites show several F-16's numbered with 66's and 77's but its not that either.
N American?