Cydrome Leader wrote:

It must be a fascinating process to get everything from various
suppliers to even fit together in the first place.

Having worked on man-rated systems long ago in a life far away I can
tell you that everything involved traces back directly to a standard .
Whether that standard is the wavelength of red light or the length of Mrs.
O'Malley's toenail on November 27th , as long as it traces back to the
standard it'll all fit .
--
Snag
Learning keeps
you young !