Hello,
I will be starting employment with the NHS at age 52 and have the option to opt in or out of the NHS pension scheme.
What is the best thing to do for long term benifit please, opt in and even possibly try to pay extra into the pension scheme AVC's ? or opt out and do something different.

If I have to pay more now for benifit later thats fine.

I am curently retired and in receipt of a police officer 30 year retirement pension.
Thanks Mike.

It really depends on individual circumstances - ie, what you're planning to put into it, and what you're planning to get out of it.