Hi Kit - just looking at your list of interests - I have a number of ancestors who lived in St. Helens (none of the same names as you, though) who converted to Catholicism in the 1870s, 80s and 90s. They had moved into the town and seem to have landed coincidentally in a Catholic area. Being surrounded by Irish immigrants, they began to marry them and convert. I also wonder if Sacred Heart Church (which is near where many of them lived) had an evangelical mission at the times, or perhaps did a lot of social work that encouraged folk to convert. They were all extrememly poor. I don't know what sort of training they had to convert, though.
Oddly, some had immigrated from Belfast, but were Protestants there.
Harlemswife