@ AndyFC
They are joystick dongles (at least the one I saw when Scala MM400 first came out was a joystick port dongle).
@ CatHerder
You'll definitely be able to sell at least 10 of those on eBay, for a Buy-It-Now price of $5 (maybe more). I doubt that legitimate Scala owners will be the ones purchasing them, because the later versions of Scala MM400 did not have dongles (I have that version), so if somebody lost a dongle he would probably have got the dongle-less version copied onto his disks either by the guys at Scala or by a mate.
Also, given the choice between the dongled version and the one without the dongle, the latter wins in terms of convenience.