Unimog Club UK

All sounds like good advice.

So to confirm from the picture above.

Green. PTO drive both, front only, non rear only

Black turn knob. Diff locks and 4x4

1 > 6. Road/field gears

Orange L, H. Is this for field and road, or for much more?

I remember this as low/high, although I don't think that's what it means in German! H is regular box, L is cascade. See lower down for more info on this...

Black arrow. Forward, neutral, Reverse?

What is the other lever for, and how does the L,H work with this if at all?

The other lever? Meaning the one with S, K, 0 and L on? That's your cascade selector. Super crawler, crawler, Neutral and I think what they call intermediate gears. They fall about half way between the same gear in high range and the next gear down, so it's kind of a splitter. You can drop down a half gear using this rather than a whole one (towing on hills is a good time to make use of it)  Gear ratios can be seen on the chart on the right side of the picture - there are plenty to choose from with this box!