Hello Malea, I totally agree with you, Thar's gold in them thar wills.

Work your way back through the Wills, then use the Land Records, to search for, Folieu.

1643 Man. Roll Ffolleaw.
1734 Dioc Reg. Fo Leaw (east and west).
1786 Paroch. Reg. Folieu heer Mx. Fo lieau, ' below the mountain.' Slieau aspirated by preposition fo.

Combined with the NSS Deeds.

Good Luck.
Averil.