You can google the tail numbers of the planes.
N40305 Aircraft Registration N40319 Aircraft Registration The planes appear to be
Maule M-4 -220C
It looks like they're both still in service, although I'm a bit confused because you say the photos were taken in 1966, which matches production years for the model of plane, but doesn't match dates listed in the tail number registrations, 1972 and 1975. Maybe they're actually
Maule M-5-220c's
