Hi Katy
I'm not sure what use you'd put an old map to in this context but if you use something like Google Maps you will find Braunston about a mile to the south-west of Oakham the county town of Rutland. The church there is All Saints and it can also be seen on Google Maps.
The other Braunstone, spelled with an 'e' at the end, is south of the city of Leicester and probably some 25-30 miles west of Oakham. I don't think that this has anything to do with your search but in case I'm wrong the local parish C of E church there is St. Peter's.
Somerby, is across the county border in Leicestershire some 3 miles as the crow flies to the north-west of Braunston, making it a very possible home for the Edward who married Elizabeth.
cheers
Tony