They are in good shape from visual inspection. They were in storage and covered, so any rust is superficial and only on the edges of the skiis and not much of it. l think they will be ok, as long as l do not do any fancy skiing (which l can not do anyway). My question is how to prepare them for skiing?

l would not even ski on bindings that old. You could buy some 3 year old bindings for $50 used and they would probably be safer. Internal part could be rusted the afd worn out and the springs could be wacked if they have been kept under tension for that long

The MRR & M46 bindings have a great design, l ski on MRR is that r 30+ years old.
As long as u have silicon sprayed & kept salt & corrosion out of the mechanisms these bindings can last a long time. l have a pair of Rosignol Skis 215cm long with an M4 toe & Rotomat FD heel that l use for spring skiing. l tested these last year at a ski shop & they were great. They do not have the multi angle release patterns of todays bindings but r functional. Liability issues on the mountain & in ski shops r unbelievable. You have to take responsibiity for ur own activitires.