The ages are a bit old but i wouldn't rule anything out unless you have a date of birth for him.
On the birth cert of Kathleen, who is the informant, if it is Esther then i am wrong, if it is James then you never know!! They just put what they were told on the certs in those days.
Its only a theory about being the same man all im suggesting is James could be Kathleens father and she had a different mother , it fits with almost everything, why we cant find a James Fanning, why they brought Kathleen back with them and why we can't find an Esther in England. Weve all got thing like it we have found in our research.
Kev.