Engine oil pressure light/buzzer on

Evening all, I have an engine oil pressure activating pretty much from start up. The engine had a recent head gasket and camshaft oil seal changed. I have replaced the sensors but no change. Sometimes after it's been running i turn it off and when  I restart the light stays off until I give it some revs but it also goes out whilst driving!

Someone suggested the oil pump (Is this an engine out job?)

Also i seem to be going through carburetor flange's quite quickly as the engine seems to be running hot. Still trying to sus out the choke as it's revving quite high until the engine is warm (is that the screw at the back of the choke which sits on the cam, need unscrewing?) Apologies for the Q's but Haynes just doesn't explain it for my carb - Weber TL32.

Trying to restore this car to use although it's looking a little sorry for itself I can't bring myself to get rid of it. Any help would be very much appreciated.