Thanks for all the responses. I checked today and it took +/-3 litres of water so clearly there had been a big burp overnight! Filled up again and had it running for 30 minutes with a good, solid, water temp, good oil pressure and oil temp got up to proper operating levels.
The oil mist was less than yesterday and only a drop or two of oil landed on the manifold. I will do the same tomorrow and see if things have improved again. It may well be "gummy" seals after 3/4 year layoff? An engine guy suggested I should do a long run with a high detergent performance diesel engine oil to clean the engine and to stop the sticky deposits forming again. I can then revert to the "normal" engine oil. Does this make sense to you?
Colin, my dipstick was removed and replaced but I have no idea how accurate it is. I have a racing sump so a high volume of oil......I cannot remember how much I put in but will check.
I will look into the PCV valve Stew as I have never heard of one of those before. I did change the water pump which is the right one from Real Steel .....rad connections to water pump OK etc.
Thanks again all.