Complex sentence: In 1953, the F-Series and B-Series adopted the 3-digit model nomenclature still in use today and the B-Series effectively became the B-600, B-700, and B-800 models.
Split into simpler sentences: In 1953, the F-Series and B-Series adopted the 3-digit model nomenclature still in use today. The B-Series became available in B-600, B-700, and B-800 models.