Very interesting pictures there

I will have to be pedantic and point out that the silver aircraft shown, #559300, is the related Northrop F-15 Reporter.

In other words, the photo-recon variant of the P-61.

The USAAF would give PR aircraft a completely new designation even if they were modified from the base aircraft after leaving the factory. See P-38E/F – F-4 & P-38G/H/J/L – F-5.