Wow! This looks very possible, given, as you say, the inheritance laws. Good puzzling it out! I have looked at those Callin wills, but haven't been able to figure out how it might work.
I am a little confused, still, about a couple of things:
1. Gilbert apparently has a second wife (mentioned in his will, but not named). I couldn't find an appropriate burial or will for her.
Why was a supervisor named for the "child at age"? Does that mean he is just barely of age, and still considered too young to manage his own affairs?
Interesting that Thomas Skillicorn is named Supvisor on ye Fathers side, and ye Ant &uncle on ye mother’s side viz: Wm &Margt Kegeen (are William and Margaret husband and wife, or are they siblings?)
2. William is not mentioned in Isabel's will, (I think--I would have to go back and double check that will). Does that mean he is the son of Gilbert and his unknown second wife? Further to this argument, William is not mentioned in Mariod's settlement--only Philip and Joney. Would that be because he is a half-brother, rather than a full brother?
3. Interesting to me that in Mariod's burial (Brian Lawson's index) she is described as an orphan. Is that how one would describe a child whose parents are both dead, but who perhaps has a step-parent? Or does that mean the step-mother had died?
4. Intersting also that Joney is in Ireland in 1699.
5. And who are the Harrisons, mentioned in Philip's will?
Thanks so much for your input. Much appreciated.