Steiner wrote: I see a picture of a para with MK II pouches and with a Sten bandoleer over the top.
How can you tell they are MkII pouches? 1/2" is not easy to spot.
The MkIII was designed with that extra height to take the sten mag.
Dont fall into the trap that 'the MkIII was the one with the QR fastening'. Eventually it was but the initial MkIII production was with press stud.
The use of basic pouches, whatever the Mk, is, for combat troops/infantry, almost universal. Bandoleers, be they sten or the more common .303 type, were worn over the basic equipment to supplement the ammo carried.
The use of the Sten bandoleer outside of airborne troops is, as the others have said, a very rare thing. I've not seen an example of it being worn by non Airborne.
So to answer your question....
For a Sten armed member of the Airborne forces it is typical to see them with basic pouches and a bandoleer.