Probably George Stanhope 6th Earl of Chesterfield 1805-1866 (i), The Stanhope family owned Bretby Hall near Burton-on-Trent (ii) so Bob may have taken the Dart from London to Sutton Coldfield and then travelled the 25 miles or so to Bretby (probably just a day's walk for a fit young man of the time)
References:
(i) https://en.wikipedia.org/wiki/George_Stanhope,_6th_Earl_of_Chesterfield
(ii) https://en.wikipedia.org/wiki/Bretby_Hall