2002 v8 leaking from both camshaft covers, also just noticed small drip from bell housing which feels like engine oil rather than ATF .started to think that maybe crankcase pressure is the problem. Have looked at Wiki, excellent write up, but wondered if anyone had any specific connection between the pcv and the oil showing in bell housing

Nothing specific as it could be the rear crank seal gone instead or cylinder head/rocker cover leak. You need to stick your nose over the back of engine and have a look. Remove acoustic cover and heater air intake scuttle (2 nuts) and have a look at the hoses at the back.

Thanks jock,two hoses replaced 2012 and still look ok. I noted your previous comments and the two videos where the guy says 70k replacement mileage . I have all the service sheets since new,and no sign of pcv replacement,mileage now 130k. Did you do yours? I am at present doing camshaft cover gaskets and washers, but am concerned that if I close those leaks and there is crankcase pressure then it has to go somewhere. When I have it back together, I will check the dipstick pressure

Yes I did mine as like you say, I didn't want the new rocker gaskets sealing it up if the PCV valve was blocked. The valve is about £35 so won't break the bank (use BMW part 11617508541, LR part LKR000040 is over twice the price). I guess you could remove and clean the old one assuming it's functioning correctly.
On replacing the valve I found one small vacuum hose had rotted apart so replaced it. I also replaced some of the other smaller hoses too as they were more likely to be blocked than the larger ones, the larger ones looked in good condition so were left.
I dissected my old PCV valve and it looked OK at 103k miles, it was probably replaced previously though.