I was looking at Maughold MIs and burial records and perhaps the plot thickens.
There seem to be several Peter Murrays in Maughold.
1. Peter Murray buried 20 Jan 1805
2. Peter Murray died 16 Nov 1843 age 64 yrs married to Judith
3. Peter Murray died 1866 age 70 also married to Judith
1851 Maughold Census
, 02?02, 104, MURRAY, Peter, Crow Creen, Head, Married, 46, Prop Farm 40 Ac, Maughold
, 02?02, 104, MURRAY, Judith, Crow Creen, Wife, Married, 48, , Maughold
, 02?02, 104, MURRAY, Ann Jane, Crow Creen, Daughter, , 18, , Maughold
, 02?02, 104, MURRAY, Margaret, Crow Creen, Daughter, , 16, , Maughold
, 02?02, 104, MURRAY, John Thomas, Crow Creen, Son, , 13, Scholar, Maughold
, 02?02, 104, MURRAY, William J, Crow Creen, Son, , 9, Scholar, Maughold
, 02?02, 104, KISSACK, Mary, Crow Creen, Visitor, Unmarried, 38, , Maughold

Brian's will site lists two of them:
MURRAY, Peter 1843 Mau A 63 0106250
MURRAY, Peter 1876 Mau E 169 0106482

Ann Quayle Murray buried 2 Jun 1789
Judith ____Murray died 27 May 1874 age 77