A bit hard to read the scale on the smaller pics but it looks like all the K90's and the BLX90 are all 364g? If so, great job by Priority One to get all of them to weigh EXACTLY the same.
BTW, this is the weight of a typical retail K90 if you string it up with a natural gut/poly hybrid, add the power pads, and put on an overgrip. I say "typical" because with Wilson's poor quality control, the weight of retail K90's can be all over the map. Obviously, Federer gets his hand selected to be as close as possible in weight and balance. Priority One then takes care of any additional tweaking required to get them to match exactly.
All of your pics are great, Fabfed! Thanks for sharing.