Merry christmas and a happy new year!
I had a mate help me sort the o rings. Surprise surprise it had been done before!!!
Ive done about 200 miles since, had to top the coolant up a tiny bit, but hoping i wont have to add any more coolant! Otherwise ive got another leak on my hands!
Thanks for your help! Saved me a few hundred quid.

Well done mate! It's not that bad of a job is it if you take your time.

Nah not at all! Just fiddly! Still think its losing a bit of coolant mind, and the o rings still look clean and dry! And heads were pressure tested, so thats concerning me a little! Any ideas?