Thanks Lorne, appreciate the advice, I'll get the necessary bits and pieces and plan to do this at the next opportunity. Fingers crossed no damage from running the engine for a short period! Be ready for more questions once I'm getting stuck into the job :-)
Np. The more questions the better for everyone as well as you. Should the forum wishes, we can continue the discussion off-group
I am optimist. I assume no damage was done. You are certainly not the first who has lost their oil pump prime with a Rover V8 engine.
However, I have a codicil. (There are always codicils!) It seems you have emptied the tappets (aka "lifters" for this international group). That is a fact that the oil pump, primed or not, will not resolve for a minute or two, depending on the viscosity of the oil you have chosen. To mitigate the unavoidable clickety-clack You can run the engine with the coil/distributor lead detached for a period if you so choose. Bring forewarned always helps us amateurs.
L.