Beyond what carguychris said, it's worth being aware that there are many differences you won't be able to see with the naked eye. These guns were made from 1978-82. Aluminum alloy metallurgy for firearms, among other things, has come a long, long way since that time. Today's 92 series guns will be far more durable than an old 92/92S/92SB. Guns with aluminum alloy frames in those days -- from Beretta, Sig, S&W -- cracked frames at what today would be regarded as low round counts.
These guns, however, are beautiful and they exhibit great craftsmanship and quality given the materials and associated knowledge available at that time. I wouldn't hesitate to grab one. Swap out the old locking block for a new one. But just don't expect it to stand up to many tens of thousands of rounds of use. That said, it's unlikely that most of us would ever shoot one enough to wear it out.