With the prize money obtained at the training aircraft competition, Arturo González Gil and José Pazó Montes created the company CAP (Construcción de Aviones Prototipo), to develop new versions.
The first project by CAP (mentioned in Aviation Magazine) was a single-engine monoplane bomber, intended to replace the CASA Breguet 19 in service with the Spanish military.
The next model was the GP-2 two-seat cabin aircraft, with a DH Gipsy Major 130 hp engine and larger fuel tanks. The only example whose existence is confirmed was registered EC-EEB and owned by Ramón Torres, who made long distance flights with it in early 1936. Some sources mention a second aircraft, but its existence is unsure.
The only picture I've found of the original two-seat GP-2 is that reproduced below, from the book by Velarde:
http://www.fio.es/velarde/
(Many pictures supposedly showing a GP-2 actually show something else, like a GP Especial, a GP-4, or a GP-1 modified with a makeshift cabin.)
There was a single-seat variant, the GP Especial, of which two were made:
- EC-BEE, owned by Lorenzo Richi, who flew from Spain to Equatorial Guinea in January 1936 (two pictures below)
- EC-FFB "Numancia", owned by José Vélaz de Medrano, who planned to cross the Atlantic with it (no picture found in original condition)
(Recent books distinguish the two-seat GP-2 and single-seat GP Especial as two separate models. The name GP-2 Especial is also found, and the single-seat aircraft are counted among the GP-2 in the article by Dario Vecino. At the time, those aircraft were sometimes called GP-1 in the press, by analogy with the standard military trainer.)
During the war, EC-FFB was registered EG-042 with the Republican air force, and was modified with a second open cockpit at the front. After the war, it was re-registered EC-AAM and a makeshift cabin was made to cover this additional cockpit.
Details of this aircraft are found in this website:
http://mchuliaq.blogspot.fr/2014/09/el-golpe.html
and good pictures of the aircraft as EG-042 and EC-AAM are found here (smaller reproductions posted below):
http://www.aviationcorner.net/gallery_en.asp?registration=EG-042
http://www.aviationcorner.net/gallery_en.asp?registration=EC-AAM