I believe the photo was taken by an American at the base as it resembles numerous other photos of U.S. aircraft at Pax River. Most if not all FT aircraft were documented while at Pax River. Personally, I believe the date to be correct.
Another example,
BuNo 04691, dated March 15, 1944
BuNo 04691 Flight Test Report Feb. 2, 1944 - July 20, 1944
http://www.wwiiaircraftperformance.o...3A-1_04691.pdf