Trouble is, the 1841 doesn't give birthplaces, only whether or not born in the county, so not sure how this will help.
Anyway, three more from the area:
HO107/270/5 fol.21 p.37
Bedford Street, St. Andrew, Plymouth
James Melhuish 30 Eg. Lab Y (b. in county)
HO107/269/7 fp;/6 p/6
Drake St, St. Andrew, Plymouth
Samuel Melluish 40 Sawyer Y
HO107/276/10 fol.7 p.7
Royal Marine Barracks, East Stonehouse
William Melluish 20 Private Royal Marines N
Barbara