Dug out my copy:
Demoiselle: 30hp VW Ardam, changed to 50hp Ardam and longer wings (and lighter pilot!)
Avro Triplane: 90hp Cirrus II
Antoinette: Gipsy I.
Eardley-Billing and Bristol Boxkite: both had a 65hp RR Continental A.65, later changed to 90hp C.90.
Vickers 22: 30hp JAP, later changed to a 75hp Continental A.75