The othher day I was reading the biography of the TV playwright Dennis Potter (by Humphrey Carpenter, who also wrote a life of Tolkien) - and I came across this:

Three of Dennis Potter's four great-grandfathers were Forest miners: Edward Potter of Shortstanding, Richard Hawking of the Lonk (adjacent to Berry Hill), and Thomas Howells, who had his own level (coalmine) at Readypenny, as well as being an innkeeper at Joyford.

Soundc familiar? So maybe the Hobbits should speak in the accents of the Free Miners of the Forest of Dean, which isin Gloucestershire, but across the Severn from the rest of England, and cut off by it from the rest of Gloucestershire, which is the next county to Oxford.