I know there is plenty of help and advice on this forum,as its almost a club in itself!!
But I am surprised you didnt join up at the beginning of your resto?
You would of got plenty of magazines,stories with inspiration,technical,help,tips,parts new and s/h!
You dont have to have your P6 on the road,or even own one to be active,and go to meets etc!!
As Harvey says,get an info pack,and a few previous issue mags,have a read,decide exactly what it is you want out of it.
Go to the websites and if they have them,the forum,of the clubs or organisations you are interested in and have a look at what they are like!
Go along to all the local shows you can,meet other rover owners and join in with them.
I actually have more active fun being a member of 2 local clubs who welcome all types of classics at show events and road runs!!