Hello,
Currently on ebay is a photo of a Curtiss Model F in Italy with John Callan at:
https://www.ebay.com/itm/12500621017...4AAOSw1gJhlC7I
I assume based on Stig's comments on the Model F being demonstrated to the Russian Navy,that this photo may already be known. Therefore rather than provide seperate links to other John Callan related photos here is one link for them all:
https://www.ebay.com/sch/m.html?item...allan&_sacat=0
Regards,
Clint