If the 74S112s are soldered and you don't have evidence that they might be faulty (what I was suggesting was on the assumption they were socketed as most of the other ICs seem to have been) then I would say don't remove them yet. Similarly until you get an ALE signal on the 8085 you don't have any evidence for ROM rot so the priority is the oscillator and an 8085. I have a 50MHz can oscillator but it is in an 8 pin DIL package and probably not compatible, if you want it you are welcome to it (is it just a simple packaged crystal oscillator or one of the larger temperature stabilised packages, my manual gives no indication of the size and shape).
Roger
