That'll be the stretch between Coombe Hill , Leigh and Twigworth.

I guess the most likely spot is the Norton / Cold Elm stretch, I'm sure the old Tewkesbury road went the short distance into Cold Elm ( Bishops Norton / Wainlode Hill junction) before the new road was built.

http://www.old-maps.co.uk/index.htm
coords 385600,223900

an address near by
2 Cold Elm Cottage, Old Tewkesbury Road, Norton, Gloucester, GL2 9LR

and the Inn nearby
Kings Head, Old Tewkesbury Road, GL2 9LR