Complex sentence: These articles attracted visitors interested in riding Disney's miniature steam train and on weekends, when the railroad was operating, he allowed them to do so, even allowing some to become "guest engineers" and drive the train.
Split into simpler sentences: These articles attracted visitors interested in riding Disney's miniature steam train. On weekends, when the railroad was operating, he allowed them to do so, even allowing some to become "guest engineers" and drive the train.