Nige, I believe all the 931's were built in Japan.
TnTrouble, I see no reason to bypass the standard 931 fuel pump, the system works just fine if the lines and tank are in good condition.
But the tank and lines can end up with internal corrosion (and external corrosion will cause pinholes and create more trouble) - and both these conditions will create fuel flow problems.
Also, tanks often have a buildup of debris inside them, such as fluff from rags, foreign materials accidentally dropped in the tank - and dirt and water (from condensation).
So a fuel tank cleanout and new fuel lines are always a good start when rebuilding - particularly if the lines display any form of corrosion.
You don't have to buy Cat fuel lines as a part, you simply manufacture new ones with some new steel tubing, and a small cheap tube bender.
Re the transmission, seals and o-rings go hard and cause leaks and shifting problems, so replacing as many as you can get at without a complete transmission disassembly would be a good move.
Check the transmission oil pump for wear levels (clearances), and the pump screen for debris and trash and look for metal. The oil pump gears should not need replacement if they fall within wear specifications. As a general rule, .003" to .005" clearance is good, .006" to .008" clearance is getting into the region where you probably should replace the components that are required to produce and hold oil pressure.
There is a bushing that supports the transmission valves control shaft where it goes into the transmission.
Replace that bushing and the seal on it, as wear here allows dirt entry. Check the shaft condition, to ensure the seal seating area, and bushing support area, are not severely worn.
The injection pump should not need attention, these old style injection pumps have a very long life as long as the filters have been working properly.
I don't have the injection timing degrees readily to hand for the PC engine, but the DI engine injection timing runs at 21° BTC.
There will most likely be a difference in timing between the two engines, the service manual advises the injection timing under "Engine Specifications".