Facinating stuff. Of course St Paul's is on Ludgate Hill where King Lud is buried.
But I thought Wan was related to the Wanes / Vanes or Vanir and so just means god?
I'd see Lugh as a light god like Apollo, who became Pol or Balder, Odin's son. So maybe Ludowanus
is another name for Balder. The 25th being the return of the 'light', and Odin being more of a stormy figure. But then all these archetypes a fairly exchangable