Hi Stig,
I was going to mention the Putnam book,but left it out of my post. Memory eh?
What your last post does appear to do is bring in to question the Mikesh and Abe information about the rear turret as an aide to identifying Kawanaishi built H3K1 because the sixth photo down here:
http://www.airwar.ru/enc/flyboat/h3k.html
does appear to show a rear turret.
Regards,
Clint