contains many references to pictures and such. https://isis-online.org/isis-reports/detail/iranian-drones-i...
Most remarkably https://twitter.com/saintjavelin/status/1577619774292606976
I think to understand the problem you need to see a list of components that are being used but also to understand that substitution is relatively easy in today's world of cross platform embedded systems. I have ordered many of these boards from places like DigiKey and Mouser. Here is on example:
https://os.mbed.com/platforms/
Many of these boards are capable of providing the flight control systems for these drones.