This mysterious plane has been at last identified by Jean Masse, a learned writer and researcher on the subject of SCW planes. This is a Lookheed Sirius - more specifically a the Republican Lookheed Sirius, serial number 149, an ex-Mexxican machine (X-BADA "Anahuac") bought in 1937. Another Sirius was present in Spain, an ex- Cuban machine ("4 de septiembre") serial number 146