Mr 89,

Sadly you need to get into the transmission to at lease fix the reverse, and the inner lip seal is the culprit-very poor design-see post 15-the o-ring on the inside.

no reverse / jerks in reverse when cold - Benzworld.org - Mercedes-Benz Discussion Forum

Your second gear could be a couple of things, but i would guess since you inspected the valvebody. The problem is somewhere else? Probably B1 and B2. Download the Master.pdf from the link above

This may help:

DIY Mercedes 722.3 722.4 722.5 Transmission K1 Piston Spring Repair Kit Install - Benzworld.org - Mercedes-Benz Discussion Forum

DIY W123 Transmission Diagnose and Adjustment 722.xx OM 616-7 - Benzworld.org - Mercedes-Benz Discussion Forum

Best of luck,

Martin