Complex sentence: Sales of the Cresco, (39 as at the beginning of 2006), have not been as impressive as those of the piston powered Fletcher, the type has been sold in several nations and pioneered new utility roles never explored by the Fletcher.
Split into simpler sentences: Sales of the Cresco, (39 as at the beginning of 2006), have not been as impressive as those of the piston-engine powered Fletcher. The Cresco has been sold in several nations and has pioneered new utility roles not explored by the Fletcher.