Projector slides of astronuats from Aug 1962

I have 8 projector slides with Alan Sheppard, Wally Schirra Jr, Gordon Cooper Jr, Scott Carpenter, Deke Slayton, Gus Grissom and a space capsule. It seems the parade is in Houston and the slides are dated Aug 1962. By research the last car should be John Glenns and this should be the celebration for the Mercury Friendship 7 return. I would like to know if anyone knows who is in this car? The 2nd photo is to show the surrounding area, this is Alan Sheppards car. I have found the photo of Wally Schirra on the NASA site under the 1962 era. Thanks for any help or direction I can be pointed in.