In reply to Houlty:
We might have a slightly different understanding of the term 'honesty box', I think for most it will evoke images of a tin you drop a couple of quid into after picking up half a dozen eggs or a sack of spuds at a farm gate. The questions seem to relate to something more like a vending machine? A halfway house between the two is probably a pavement newspaper box where your coin unlocks the box but you're trusted to only take one per coin, not something you see in the UK.
Good luck with the project.
jk
