Getting bounced clean out of the spare wheel when we hit a rut at speed [ about 25 probably] was somewhat scary , came back down on the NS wing and held on just thanks to the old series having those actual wing mirrors on stalks..

Could be the ball at the bottom of the gearstick is worn.

Fill the system through the rad plug. I found it was better if parked nose up hill a bit. Put heater control to hot. Run engine and top up as needed. If heater now starts to warm up you can be pretty sure all air gone. Replace rad plug and check expansion tank about half full.

From what I understand it was some sort of protrusion on the cog that prevented pully sitting tight and square against it.

Yours is nowhere near as bad as the one I described in my post above, yours is the later type as in pic above [ early Disco 200 had a very steep taper on the end of the crank] Looks well on the way to a fix. I would use a new crank bolt. Good luck.

Pic above is of later crank with no taper. Some twenty years ago a mate had a similar issue on a 200 in his disco and asked for my help. He was a bit short at the time and asked If I was willing to have a go at a "bodge" repair. The pully had spun on the taper, worse the woodruff key slot in...

As above, and if there is a tad of air left the injection self bleed will soon sort as engine fires up. Filling filter most the way before screwing on saves a lot of pumping on lift pump lever.

What type of alternator do you have?

When being overtaken by HGV on motorway as their tail end passes you give a head lamp flash to indicate it is safe for them to pull back in front of you. They appreciate it.

Adjusting box must only be done with the drop arm and wheels in the straight ahead position and must not be over tightened.

If all rads in good order check engine and oil cooler thermostats are working. Uprated coolers available from Allisport, Fit up front where it gets an air flow.

Bare galv on series every time, prefer on my Ninety as well.

And there is always the old earth issue, without a decent earth electrickety will find any way it can to complete the circuit

You are correct in your assumption it is a 12j, pretty much a straight forward fit into a series. Has cambelt.

Need clearer description of issue. Bottom pin? Is this the shaft coming out of steering box? Or where the drag link connects to end of drop arm? Possible cause of play. Drop arm loose on box shaft. Bearing/shaft worn where it exits box. Ball joint on arm worn. Sloppy steering can be the...

My Series 3 farm run around 2 1/4 diesel has only the down pipe at the moment, It is LOUD.

Loudly crying, if you try it. You will be deaf and Plod will give you a ticket. Straight through suits a turbocharged unit because the exhaust gas as it passes through the turbo gets smoothed out resulting in less of a bang.

Just remove the muffler you have and you will soon know.😭

A basic tension test for a V belt. At its longest length between pulleys grab between finger and thumb. Twist belt and if you can turn it 90 degrees that is about right. Cant turn it too tight, more than 90 too loose.

And likely in warmer times half your time will do.