Hello,
Currently on ebay is a photo of Macchi M.13080 flown by Prince Aimone di Savoia at :
https://www.ebay.it/itm/S-A-R-AIMONE...gAAOSw-rReClDq
The caption has the machine as a M.7, but I have other Macchi flying boats in the 1308* range as definite M.5 machines.
Regards,
Clint