Ah, I think I almost do get the Uxbridge thing ...

Oxford English Dictionary ...

Oxbridge = (accepted amalgam of Oxford-Cambridge)

Uxbridge = slightly left of centre allusion to "Oxbridge", with the added bonus of Uxbridge being an actual place which in reality has no relevance to either Oxford or Cambridge

Uxbridge English Dictionary ...

Nobody could accuse me of being slow on the uptake, could they ...