Engine revving 320i

Hi there, I have a 1988 BMW 320i. It was bought new here in New Zealand back then and only has 123k on it. It is in a very original condition and is really nice to drive apart from the issue I have with high revving on start up. Whether it is hot or cold the engine will rev at about 1500rpm and when i am braking it takes a fair bit to stop it with it being automatic. Any help would be greatly appreciated.

Cheers
Brendon