One of the people I’m subscribed to on Youtube posted old footage of the first Japanese Grand Prix in 1963 in two videos. Unfortunately he/she does not permit embedding, so I can only post links here.

The first video shows the introduction of the Grand Prix. Then it features a GT race in which a Nissan Fairlady SPL213s wins of a few other cars like Triumph TR3 and TR4, but I also spotted a Austin Healey and a Porsche. This is followed by a touring car race which is very spectacular! A lot of entertaining sideways action with old Japanese tin like the Prince Skyline ALSI-2 and Skyline S50, Toyota Crown S40s and Nissan Cedrics. In my opinion this is the most enjoyable part of the two videos!
Japanese Grand Prix 1963 video #1
Japanese Grand Prix 1963 video #1

It gets followed by the second GT race which is a bit less spectacular than the first but it still contains some really good action.

Then the introduction of the Grand Prix itself which gets started in the second video. Personally I didn’t really like the Grand Prix itself that much after seeing all that action beforehand, but I can imagine the Japanse viewers back then thought the exact opposite!

Japanese Grand Prix 1963 video #2
Japanese Grand Prix 1963 video #2

You can watch the videos here:
Japanese Grand Prix 1963 part 1
Japanese Grand Prix 1963 part 2