Can anyone advise on the noise my 1995 Discovery makes? It has a manual R380, LT230 transfer and has done 98k.

You may need to sit down for this

At low speed, I get a hissing/ scratching noise coming from somewhere, only when in gear. I can best describe it as the noise you get from a brake disc when the car has sat and it's gone rusty.

I can hear it from approximately 10mph, and think it is there at all speeds after that, but the other noises must drown it out.

If you coast in neutral, the noise is not there.

If you select any gear, even before you let the clutch back up, you can hear it start again, as long as you're moving at over 10mph ish.
It is loudest in 1st or 2nd gear.
There is also a gear whine from somewhere, proportionate with road noise but I'd say that's probably on par with most 21yr old Discos and for all I know, could be something unrelated.

Apart from this noise, the old crate drives as you would expect, everything works etc but the transmission in general feels a bit gnarly- it clunks, clacks and rattles but nothing unusual compared to others I've had.

Only other thing is 1st and reverse are often difficult to select and commonly only partially engage, leading you to 'have another go'

Anyone had this before?

Handbrake shoes binding a bit maybe?

I was hoping that would be it.. but sadly not! It does sound just like that though.

sounds like the baulk rings are worn , could be bearings spinning in the case ,worth dropping the oil out and looking for filings or metallic shine

I did a full oil change on both boxes and both diffs a month or so back. The oil from the gearbox and transfer were both very... grey and shiny with plenty of hedgehog affect on the drain plugs.
If anything, I think the fresh oils have made it all noisier