Tell me please anyone - is 3rd gear the synchromesh that usually packs up?

Symptons:
Initially, gearlever started to feel a bit strange, sort of wobbles as I push into 1st or reverse, as if the clutch is dragging (it isn't)
A funny noise (plenty noises to start with) developed, like a light mushing waterfall noise, even in neutral idling.
Later, can't get into 3rd without changing at exactly the right revs or double-de-clutching.
4th gear starts to feel a bit strange on the lever, doesn't jump out but lever makes me think it wants to .
All the time, the swishing noise (like someone dropping a long light chain) gets more persistent and slightly louder.

All comments appreciated, inclusing the extent of damage being done by any further driving.

Thanks,

Clive
'88 2.1 Syncro Transporter