Wheel bearing or kingpin bearing?

Hey folks

One of the above has failed/is failing on my Jim front axle. Looking for pointers as how to tell which. Symptoms are:
1. Front axle oil leakage dripping down both front tyres.
2. 4wd flashing light, this was a gradual failure. It was sort of working in February, you had to turn the ignition on and off a couple of times & it would eventually switch, now doesn't engage at all. I've been told this could be related to wheel bearing failure? Pipes at back of wheel hub appear fine.
3. Occasional strange steering clunk, couple with slight resistance to wheel turning which frees up after 'clunk'.
4. Slight wobble at ~45mph (~75kph). It's done this since I bought it 6 months ago, hasn't appeared to get better or worse.
5. Slight intermittent squeeking noise when moving, sounds like a worn brake pad (could be a worn brake pad, can't tell past the 5 spoke wheels)

Out of of those symptoms does any one scream one fault in particular? I have always associated wheel bearing failure with loud droning, but I am aware that on some vehicles this doesn't happen. Haven't lifted the vehicle to check for play yet, but am I right in saying both a kingpin and wheel bearing failure would cause play, or would kingpin play only be laterally? Also I am kind of thinking no.3 is the spring but both seem fine. Car is 115k miles, 12 years old so wheel bearing is within the realms of normal wear, as is I believe king pin bearing.

Wee update:
Decided to pop the jimny up in the air well there was still a bit of light.

No discernible play in either front wheel in both horizontal and vertical, no noise when rotating left wheel, very slight 'hissing' sound when rotating right wheel also a slight resistance to rotation over the left side (video: ) Not sure if this could be a slightly binding pad? Or is this fairly conclusive as a wheel bearing, doesn't sound 'grindy' persay, that being said the only other bearing failure I've experienced had a fairly pronounced drone at speed.

Wheels off, both pads in good health, springs are slightly crusty but niether is snapped. I had a closer look at the pipes, not 100% which ones are the potential problem ones for the 4WD system, there are 3 in each hub coming from the direction of the diff, one is easy to trace and goes to the lower section of the hub with its own 'port', these are fine on both sides, the other two seem to go down into the hub, I've traced them as far as they where visible and they had no splits, not sure how to trace them all the way to their ports without taking the brake disc off.

Sorry for being slightly oblivious, very amateur mechanic here, I can do pads and services & that's about it

Righto, ordered up 2 kingpin + swivel seal kits from Martin, just a wee query though, it's obviously been leaking a while so I'm going to do the front diff oil as well. I already have 3L of TRIPLE QX EP 75w90, which says its GL4 & GL5 and ZF Syncro rated. I'm right on saying you can put GL4 in a GL5 box but not visa versa (something about brass bearings?). So the fact its rated for both is OK for the GL5 diffs?

Also do you reckon 75w90 will be fine, I know with engine oil it tends to be best just to get the lowest cold weight you can afford as it allows the oil to lubricate better on start. But manufacturers spec higher minimum cold weights to lower servicing costs. Does this same principle apply to diffs/gearboxes?