Random pic borrowed from the web, ignore the arrow.

Pretty sure that is the wrong hole, I think it is at the top ie 12 oclock, it is a round hole in the alloy casing of the injection pump. I am not sure if I have any pics, but will take a look.

That is called a hard reset, disconnect battery leads from battery, join lead ends together for a few seconds, this discharges all the capacitors etc in everything on the vehicle, reconnect leads and thats is it. Sometimes have to do this when you cannot get fault codes to clear, but you have...

No idea (to lazy to look!) on the pressure the facet pump delivers, but you can tell when it is not switched on, it only really makes any difference at higher rpm as the bosch ve injection pump also has its own built in vane pump, so as an anti theft device it is a no go on the tdi engines, but...

Iirc it has to be over 40 years old, and is to do with the month registered, so you might have to go 40yrs and 4 mths for example? You still have to tax it even when it becomes foc, can be done online and literally takes a minute or two.

No idea, but like most things LR it just might, would certainly be a neat solution, oh and I think that is a 300 vac pump, the 200 vac pump fits where the series inj pump mounts. I fitted a cheap copy facet elec fuel pump to my 200tdi years ago as was sick if lift pump issues, been fine all...

For testing just run a wire from the battery positive terminal to the stop solenoid, it should click as you apply the wire, this does not mean it is working, but it is a good start.

Probably the cheapest starting point, it is after all that time of year. If keeping the car get yourself a code reader.

Apply battery voltage to the stop solenoid and try it again, have to remove the wire to stop the engine.

Welcome to LZ.. Any codes?

Your mate sacrificed a socket for the cause, a man after my own heart.

Has it got a throttle cable?

It could be total coincidence and actually be another fault, ie fuel tank cap breather blocked, air leak into the fuel lines incl the lift pump, any rubber fuel hoses fitted? Was there much fuel in the filter when you checked it? Yes pulley slots on the injection pump pulley, these can be...

It is quite an easy job to adjust the timing so long as they sert the new belt up with the bolts in the middle of the cambelt pulley slots, otherwise it is a strip down job. It sounds rather quiet for a 200tdi, so maybe the timing is in the retarded position? I

Check for voltage down the charging light wire with ign on but engine not running, then check for volts at the battery with the engine running. I take it none of your horn wires go anywhere near the alternator?

The bosch ve pump will self bleed, so if you have a small air leak into the fuel lines the car will still start but have a rough idle until the inj pump has a clear supply of fuel. There is no idle cable, there is an idle screw. A quick google of bosch ve injection pump will get you loads of...

Sounds to me like the fuel screw has been wound in to much and this can raise the idle, the black smoke is a clue someone has been messing with it. Oil on 200 glow plugs is quite normal.

I would hazard a guess any servo will pretty much work with any vacuum pump.

Gear lever = 6 speed, twisty knob = 8 speed, at that age both will have the 3.0 litre engine.

I saw that in your first pic, which I why I included the pic of the latest version in post number 29 as yours in no longer available.