Hi Hans,
You might be interested in my June 2019 posting here on IceInSpace entitled :-
'"Guidance is internal". The remarkable Saturn V ST-124 inertial platform'
that also includes photos and a link to a pdf :-
"A GENERAL DESCRIPTION OF THE ST124-M INERTIAL PLATFORM SYSTEM"
by Herman E, Thomason, George C. Marshall space Flight Center. Huntsville, Alabama, NASA document, Sept 1965
See
https://www.iceinspace.com.au/forum/...d.php?t=176004