Hello Mary, here is another mention of, Booillee Velt, with some document references to search.
Maughold and Ramsey Place-names by William and Constance Radcliffe
BWOAILLEE (YN) VUILT – Fold of the wether
Boile volt - Lib. Caus. 1684
Bollevolt - PR 1706 - (Parish Register)
Booillee Velt – EF 1768 - (Enquest File)
Bwoille Velt – NSS 1815
Bwoailevelt – CD 1824 - (Castletown Deeds)
Originally part of Ballaberna, this has been a separate farm since the seventeenth century.
Averil