2 belts, one does the power steering, water pump and alternator. The other has to come off first and is for the air con. Did both belts come off?

Would indicate aux drive belt. Drivers side, UK,

If its the type of push fit that pushes into the fitting, a spanner just bigger than the pipe will push it down. They can be quite stuck in though.

I would check compression first. Does the heater get hot too? After the hg was done was the whole cooling system flushed out as it may have become blocked when the fluids mixed.

Is the starting issue long crank times or slow turning over/ battery flat. I think the battery reset alters how much it is charged, so should still be charged just maybe not to the new batterys capacity.

On the fl1 does diagnostic live data show requested boost pressure and actual boost pressure? that would prove the turbo is activating ok.

Yes that's them. I know not close but they know their stuff

I'd say find out what it is first. Rear diff can cause issues and is a common failure point. Bell Engineering are knowledgeable and it may be worth a chat or drive over there.

Is there a reason to put the filter in the chamber rather than the cap? I've only put mine in the cap first and never considered putting it in the chamber first.

That i don't know, just thinking all a diesel needs is fuel air and compression to start. There should be some live data you can monitor showing air flow and fuel pressure.

Maybe not air ingress but lack of air if the throttle body sticks shut.

Well Riddler, looking at Google images it should be by the hinge somewhere, probably behind a rubber cover .

Did the cam belt survive? If not you could be looking at new valves and if one or more broke new piston. I would take off head first to see damage.

What you could do with knowing is the current for each glow plug. If using clamp on meter that would prove connection and glow plug heating up.

First thing is to get it running, any bits missing? Battery good? New fuel in? From there other options like easy start. If doing it yourself, it's only nuts bolts and magic, get a code reader like the ebay elm ones with phone app(free is good). Decent six sided sockets and any other tools...

Possible, in my freelander 1 I had an insurance tracker plugged in, that was constantly powered. Although the drain would be very small. 3 to 4 days I wouldn't expect any difference so maybe the cold has tipped the battery over the edge.

I found a syringe, can get from chemist, is useful for filling as long as you don't squirt it too fast.

Are they higher than the filling plug? Worst case some oil comes out and you can refill.

Try the manufacturer for opening instructions or if they can recommend a lock smith. For 300 you can buy a nice angle grinder and new cabinet. Just grind the gap between door and cabinet then fit new lock

But didn't say where the noise was from!? No noise when stationary would rule out pump. I'd start with the brakes and pads first if they need doing