3.5 V8 coolant and oil pump problems

Hi all
i have a 3.5 Carb in my 90. im in the last stages of rebuilding the landy and it has been studd for around 6 months.

My problems are:
Ive been trying to wire in the Oil pressure light but i cant get it to work this is either down to a faulty sender or there is no pressure from the oil pump. ive ran the engine with a rocker cover off to see if there is any oil to be seen coming from the rockers but i cant see any. im scared that there may be a pump problem and no oil getting through.

my next problem.
I have a small oil leak from the vally gasket and also as the engine got hot the fumes coming from the flame trap had some steam in and i felt that this was due to the vally gasket again leaking. ive chamged the vally gasket for a new one ( the fancy type with a black coating) and there is no oil or coolant leak but there is still this steam going from the flame trap. is this just coz its been stood for so long. or is it coz there is still water in the oil or is one of the heads leaking. There is no over pressure in the header tank and there is no oil in the coolant. I fearing the worse and its a head problem

can anyone shead any light on this??

did you prime the pump?

Is it just cos the inside of the engine is hot and its cold outside at the moment??

yes the pump was primed. when i first got it going i did put a test ligh on and it was ok with pressure there