Finding original textures not supported by a paint kit (like comp and interior)/opening files with supercompression scheme 65536

Hi! I've bought the airliner and installed it. I would love to create my own livery, but i would like to modify more than files given in official paint kit... I would also love to adjust comp layers for fuselage and engines, minor details of interior (like seat screens, seat colors, add a little sticker with available weights in cockpit, etc.). Where can I find the base texture folder?  Or is it possible to enrich the paint kit with at least comp layers for fuselage?

I've gone through packages and community folders and found nothing... 😞


Edit:

Even though I've found those textures, I'm unable to open them... Photoshop screams about unknown supercompression scheme 65536. Any tips?

Edited October 10, 2025Oct 10 by Pionites