The first two sound like features, not problems.

The ABS / OVP fuse blowing - that's a real problem. Have you tried reaching out to MB clubs overseas, in Germany or the UK? I'd try to locate those types of organizations. You could also try the MB Classic Center in CA and see if they can help you locate a wiring diagram. Very rare car with all those options, definitely worth keeping her ship-shape!

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC