Paddington and Slough have a history of being eastern suburbs of Wales,
thanks to Brunel's GWR,
not the proud, (but these days, distastefully, a bit Ukippy). Domesday Book village of Ruislip.
I think we have discussed this before. The conduits into London depositing the diaspora at their respective entry points; the Scots in King's Cross, the Irish in kilburn, the French in Croydon...
He's from Wales.