GREGORY XVII (?)  Italian cardinal-archbishop of Genoa (1946-87); papabile in the conclaves of 1958 and 1963; oft-referred to as the Pope in Red.
 
SP - Signed Photograph - no date but as cardinal-archbishop of Genoa. Black and white image signed in blue fountain pen ink on the lower white mount.

According to numerous reliable sources, Siri was elected supreme pontiff, taking the name Gregory XVII.  It is widely assumed that, upon abdication due to pressure from fellow-cardinals, he was obligated to never speak publicly about the conclave proceedings. According to the late Father Peter Khoat Van Tran …He, Pope Gregory XVII, admitted in front of me that ‘he was Pope Gregory XVII’…His (this) confirmation took place in Rome on 14 June 1988.