Thank you all; it all went well and with some fresh slicks it would be better still, but as I'm just 0.47 shy of the PB they aren't too bad.
It is also £1050 for a set.....so don't have a permission for that one.
Bought a new lithium battery and fitted it as the huge Red-Top was 11 years old and sometimes just gave me a reminder of it's age.
The new one is stupidly light in comparison and sure gives the starter more urge when tested, £140 well spent (mate's rates).
So I will now have a corner weight issue as the left side is about 15Kg lighter, or I can scoff more bacon butties now.