UPDATE
So i had a look at the vacuum pipes to see if they were all connected and they were. I then had a look at the vacuum tank if it had any damage or leaks etc and it was all fine.
What the issue was that one of the vacuum pipes had a very tiny hole on it that was not really noticeable to the naked eye.
I removed this pipe and tried blowing in to it and then I could hear a hissing sound.
Once the pipe was replaced i started the car and drove it for a bit. There was an immediate improvement to the acceleration and also the sound of the car was much better.
Thank you for all your help in helping me fix this issue - much appreciated.
Thanks