This clearly a case of having too much time on your hands. The first thing that you should have done is lit the motor off. Before cleaning, before painting, before anything. Then you have some idea what you are dealing with. Right now you could be putting lipstick on a pig!
Before you go any further with ANYTHING light the motor off.
FWIW, nobody on the outside can match what the factory does when they manufacture these motors. "Rebuilding" one, usually means just an overhaul. A rebuild means that every working surface is NEW: reground crank and cam, rebuilt rods, new bore job and pistons, new oil pump, valves springs, guides, etc, etc, etc. $$$$
Just doing rings and bearings and maybe a valve job is a HUGE step BACKWARD in a good motor.
Get it running, verify oil pressure and no obvious knocks, etc. THEN check the compression.
FWIW oil pumps almost NEVER go bad except when they get FODed. That is when broken pieces of the motor get sucked up by the oil pump as the motor is disintegrating. I have been inside of hundreds of bad motors of all kinds and I have never seen an oil pump fail on its own. I have seen them smashed by big heavy chunks of cast iron and steel. I have seen broken gears and rotors when they choke on debris. I have never seen one as the primary failure. If you think about it, the oil pump is the first thing to get oil and the last to lose it. By the time it fails the motor is only minutes or seconds from the scrap pile.
CAVEAT: There are things like some Subarus and SAABs that have such marginal oil pumps that tiny amounts of bearing wear will cause low oil pressure, but these are well known and a new pump never cures the problem. A bigger oil pump does however.
So when somebody tells you "the oil pump failed", it means they ran it out of oil.