I agree with cheezy that the 1st is sprite, and like amigos said it probably is the correct/original engine I woudl say late 70's early 80's the next newer version of that frame they went to a molded foam seat.
I think the 2nd bike, while highly modified, was originally a 2nd generation foremost "golden pinto"
They briefly had the rear axle plates like a lil indian does and a disc brake in 1970, I think it was the first version of the bike built by Bird, the 1st "golden pinto" was made by Arco.