Estimates of children's birth: Phillip 1670-75 [named as heir in late 1684 but u/a, at age in early1690]; Joney & Margt 1676-1684 [under 14 in both]; William 1676-1690 [possibly of 2nd marriage]. If Gilbert was married by 1666, there may have been other deceased children 1660s-1684.

I assumed that the Thomas Skillicorn named in Gilbert's Will of 1690 would be an established member of the community?. If he was Thomas s/o Gilbert Skillicorn, he could only have been at the most perhaps 10 years old, and hence not capable of being a supervisor?. [Oldest brother Henry born 1678; he left the Island for fame & fortune elsewhere leaving second son John as the heir [see all the property records involving John & mother Elizabeth + Elizabeth's/Isabel's Will 1721+Thomas' children's Deed of 1725]. Thomas was farming in Agneish when he died in 1717, so I assumed he was the 3rd brother, born 1680-85?]
Rgds
JohnL