Hi Richie, welcome to the forums. We planted several crab apple whips the year before last, and managed to keep them watered through the hot summer last year, but they are not looking all that happy still, and are without blossom. I wonder if the hot summer caused the problems? Our trees are the wild ones ''Sylvestris'' but we have other more ornamental varieties, and have found that hard pruning can be very successful in shaping them up and providing more nice new growth. As yours are so big and old, pruning might be worth a try. Winter though would be the time to do it.