Greetings,
Well, for a start you have a fair amount of cousins in the US, but perhaps you knew that.
The ancestory and descendants of the Fortunes of East Fife (Barnsmuir and Muircambus) was researched pretty thoroughly by my 2nd cousin Ernest Fortune in conjunction with Effie Charlton Fortune, William Ranken Fortune's daughter, who was an family history enthusiast as well, having been sent to stay with her maiden aunts in Edinburgh to study when her late teens.
Ernest drew up a series of sheets accurate to about 1975, I think (I haven't looked for a while), which were fairly widely circulated among the UK tribe and in America as well via George Fortune who lived in Carmel. Ernest's son George, who now lives in France, has all his father's papers and has been doing some work collating the information digitally.
Of late I have been looking into the life of William Ranken himself, our gx4 grandfather, who served in the War of American Independence (losing side) and first had the tenancy of Barnsmuir. John Fortune , later of Muircambus, married Captain Ranken's daughter Christian.
I am afraid I don't have much time to spare at the moment to get into long narratives. How much of this do you know already?
Rgds JF