It’s not quite the same, though: here, Jell-O comes in powdered form, in a packet inside the distinctive box. Easier to mix than the UK’s squares of concentrated wobbly gelatin, but somehow less fun. Part of the jelly-making process was always ripping the squares apart and, if you were lucky (or naughty) keeping a piece to eat. Chew it, or let it dissolve in your mouth? I never had the patience.
I rather like the idea of the Margarita flavour, though…