if its not to big for its space I'd leave it alone to be honest.

When did you prune it last year? They usually dont mind a good hack in spring.

GQT on the radio said in answer to a question that they do not like dry sandy soil-- the question was about the hips but maybe why you've no flowers, try a high potash feed in spring and according to GQT plenty of water-- last spring was very dry in some areas

Also, some of the older varieties are reluctant to bloom on new wood, so a heavy pruning in early spring--as for modern roses--could have prevented bloom that summer. Do they seem to be in good health, otherwise?You might want to wait until after the first flush of bloom in early summer, then selectively cut the longest branches right back.