I have 34th Regt stationed on Island in 1835 (ref Manks Adv 15 May 1835 ) so it looks as if he decided to stay on the Island - The Peel licence ref was just for 1 year in 1830 - maybe I'll go back and check on date though the family did settle there and the 1830 date fits with birth of two sons
The 1841 census index would however seem to indicate an older John Sheard in Peel
SHEARD John 35 Dou 6 51 301
SHEARD Margaret 4 Dou 7 40 198
SHEARD Daniel 15 Pee 2 2 10
SHEARD John 75 Pee 2 2 10
The young Margaret appears to be staying with a John and Margaret Cannell
maybe Brian can fill in details
SHEARD Julia 45 Pee 2 2 10