You really should take a trip over to Cleeve Hill near Cheltenham. It's about 25 miles from Moreton, so you'll be nice and warmed up ready for the 25% horror. I ride in this area all the time, but realise I'm completely unable to give you any details or directions, which is actually quite worrying. A starting point could be the route of the 'Circuit of the Cotswolds' - it takes in a lot of the most interesting bits [climbs] in the area:
www.circuitofthecotswolds.org/route-map.php
Sorry not to be of more help