Hi Stig,
Yes I was guided by Varriale and also Gentilli and Varriale I Repart P.393 has a photo of that machine captioned as belonging to 259 Squadriglia. With moderate confidence (note the use of US national security speak there

) I also believe the machine is more likely to be 5595 rather than 5593 as the firs two and the last digit appear the same.But, of course its not cleat enough to be certain.
Regards,
Clint