Complex sentence: The 266 model offered very good quality and powerful engines for a low price, so it was sold in various countries for many years (not only in the Eastern Bloc; for example it was used by the army of Yemen).
Split into simpler sentences: The 266 model offered very good quality and powerful engines for a low price. It was sold in various countries for many years (not only in the Eastern Bloc; for example it was used by the army of Yemen).