Hello, Elle!
That "kettle" is not in my old Chambers, but I have seen it used on the News several times, when police are confining demonstrators to prevent them marching.
Could be, I suppose, that it is only a Scottish term?
Is it not in your much newer Chambers?
I have looked up "tombola" in Chambers, and it states that winning tickets are drawn from a revolving drum, I think.
So, the clue looks fine?
Hello, Malone!
Yes, your "tombola" parse makes good sense.
I should have looked it up in the dictionary earlier!