That's very interesting indeed, and might help shed some light on the fact that between 1891 and 1901 many of the Locks travelling north Wales adopted the alias Boswell. So, for example, Noah Lock (born 1824) was Lock when seen by the census taker in Edgmond, Shropshire, in 1891, and Boswell when at Llasadrwn, Anglesey, ten years later. He and some of the family members who travelled with him remained Boswells in the official sources until the end of their lives. So, old Noah died in Llanddeusant, Anglesey, on 12 March 1907, and his death was registered as Noah Boswell. His wife died three years later and was registered at Bangor, Anglesey, as Deliah Locke-Boswell.
If you think it might stimulate your grandad's memories let me know if I can tell you more about the activities of the family during the early 20th century.