The one on the left side of the dashboard is the type of brake tester they used to put on the floor were the front passenger sat. They would do a short drive and come back with their opinion about your brakes. Mine always passed as I maintained them well.
The other devices in the picture I believe do a similar job, and are just to show what testers used in 1965. By certainly the late sixties, I saw only the aforementioned brake deceleratometer being used. After all cars were so basic then, so testing as I witnessed was very simple.
My regular tester at a local SE London garage just used a small hammer to tap the chassis / floor pans for rust and passed my A40 every time. The chassis though was so rotten the body was not attached to it, and the cross member supporting the front passenger was not attached to the chassis or body; floating in the air!!
Yes, MOT tests were simple then and let our old bangers go around long past their use by date!