Wayne, thank you very much. You've provided much new information for me.
Regarding John and Jane (Raisbeck) Gelling (Frank's parents), they do not appear in the 1891 census in England, nor can I find a burial or death for them there (you provided the death for Jane in Wisconsin). I suspect they emigrated to the US in the 1880s, perhaps in 1883 which is the date their daughter Georgina claims to have arrived in the 1900 Darlington Wis. census. Georgina would have been about 19 in 1883. Younger brother Robert Raisbeck Gelling (age 16 in 1883) is in the 1891 census as a Draper's Assistant age 23, with his aunt Mary Ann (Raisbeck) Stephens, widow of George Stephens (a draper) at 2 Aston Road, Birmingham. Would his parents have emigrated, leaving a 16yo behind? Maybe they emigrated later in the decade.
You said that the 1900 Darlington census for James & Georgina Hoskin indicates that son John was born in 1881 and Christopher in 1883, both well before the 1888 marriage. Would they be children of James Hoskin from an earlier marriage? Presumably they're not Georgina's.
I think that's the end of my questions. Thanks again.