Mystery combo change key

[Huw Eastwood]

This ones really got me guessing- was sorting through a box of assorted combination change keys and came across this 'baby':


It's like a standard S&G key for the 6730 3-wheel but its much smaller- the business end square section is considerably smaller as well.



At first I thought of an 'economy' range that S&G made in zinc-passivated pressed steel. I saw a few on wall-mounted key boxes back in the 1980s here in the UK. I think it was Securikey that offered them as a combo alternative to the Dom pin-tumbler camlocks they used as standard. Anyway I since remembered that the change keys for those were a round section with two flats, and I've since found one, leaving me more mystified as to what it's from?