Today you get a two-fer — two Mariner images scanned from slides I took way back in 1989 at JPL:
The image on the left is of a small table-top model of the spacecraft, while that on the right is of a full-size mockup (maybe engineering model) of it.
Mariner 5 was originally built to be a backup for the 1964 Mariner 4 mission to Mars, but since that spacecraft worked so well, Mariner 5 was modified for a Venus mission, and launched to that planet in 1967. Not carrying a camera, Mariner 5 still sent back information on Venus’ weak magnetic field and hot surface temperatures, as well as information on the interplanetary environment. During its mission, Mariner 5 flew closer to the Sun than any previous spacecraft.