That's not easy at all.
<> row 2 is fine for most languages, but not ISO UK.
And each layout has different symbols on the right of P, L and M.
Also, the symbols on the number row can be different from language to language (for example on italian layout I got "&" above the 6).
So it's actually a mess. Blank keys could be an option, but to fit every symbol we should get 10/12 of those. And a number row with the numbers only? I don't know. It seems a bit nonsense to put so many blanks on a double shot set!