The Royal Enfield agent in Cardiff was Robert Bevan, of 31 Castle Street, and was great at solving holiday problems. Today the place corresponds to one of those boarded up shops you see in the picture
Bevan motorcycles was founded in 1897 and was selling Royal Enfields as early as 1911. See this ad from 1912,
Remarkably, they are still in business today, but moved, in 1998, to a new location.