Pity about PYY, I did a lot of work in it for National Mapping in the 60's. The after-market turbos were hungry on maintenance, great for performance. Officially flat-rated at 29", and approved to 25000'. Actual ceiling about 32000'.
For "happy snaps" a 45 deg bank gave an interesting oblique. And one customer was so desperate for information that we established just below the high cloud that covered their area, in a 45deg bank with the camera firing at max rate. Similar results to the WWII tri-met.