how does a chap tell?
What I do? What I earn? What my parents did? Where I went to school?
21 years after moving to this country and still fail to understand what is left of the class system, I'm afraid.
You have no place in the British class system, being foreign. You might be considered an honorary nouveau-riche arriviste at best, but in general grubby foreigners rank somewhere below dole-scroungers in the British hierarchy.
And quite rightly so, if I may make so bold as to venture an opinion. My right to do so being arguable, given that I am quite foreign myself.
It really is terribly complicated. Basically there are several class templates that all overlay each other, allowing one to exist in various classes simultaneously.
For example, a good friend of mine enjoys at times the profile of a terribly proud, gritty, working class northener (especially when drunk) but is equally happy to play the middle-class southerner when proving his urbane, cosmopolitan pro-EU credentials when he needs to impress his peers.