I think we may not have the same line, regretabbly.
In my records from late 1500-s to present day, I don't have one single 'James'!But lots of 'Ralph Allen's'[Allen being the surname, but as surnames changed through female Allen marriages, children began to be called Ralph Allen.....(followed by new surname!!!).The first Ralph Allen became a very important man in the postal system and for exploiting Bath stone and the building of Georgian Bath; his sister's children became 'Daniell's', in Cornwall, and one, c1800-1823 was known as guinea a minute Daniel for the amount of money he was making!.His christian names were Ralph Allen.... He had 18 children all of whom had children, first boy being called.... you've guessed it, Ralph Allen....whatever. I have Philip/s; Reskeymer/s; George Edward; Henry Edmund; for the period you mention, but at present no James, and doubtful of any turning up during that period.Although this can, of course, change.
Do keep in touch if you feel I can help further.
By the way, the early generations were involved in running the Coaching Inn at St Blazey (The Duke?) and also the Coaching Inn at St Columb Major, where Ralph Allen's grandmother clate 1500s - mid 1600s also ran a post office, hence his footing and interest in the postal system..