Hi, Plumberdv.
I think that I can help clear this up, since I believe that you got the knife from me. I had picked up a pair of brass spacer, brass rocker knives at about the same time (4th/1st from '70-'72). I cleaned them both, using my index finger, an old sock, and Brasso. Since I don't own any power tools for grinding or buffing, I usually work until the brass is clean, or tendonitis sets in. I realize that some have issues with cleaning but, after it happened a few times to me, I decided that I would not pass on hidden scratches, corrosion, etc. to anyone else.
While both frames turned out to be in great shape, the blades had been marked up pretty good by poor sharpening technique. They were nearly full, but scratched and a little wobbly. So, I sent them to Buck for sharpening and blade buffing to complete the restoration, thinking that the nice frames deserved better looking blades. When they came back, I was surprised to see that Buck had decided to replace the blades on both. They had assessed the blade play and determined that it was too much and went ahead with the replacement. Apparently, tight blades make a knife work better! Who knew??
My initial reaction was shock. When my pulse rate returned to normal, I contacted Joe about it, and learned that, if you're concerned about maintaining the originality of a knife as a collector, it's best to work directly through him when having knives worked on. It's also best to be crystal clear with your instructions to the repair group. He generously offered to try to find a couple of vintage blades to put in the knives, but I decided that I would look for new homes for the knives as they were, with the new blades included clearly in the ad descriptions.
Anyway, there are only the 2 variations listed for separate brass spacer; the brass rocker rivet and the stainless. I think that if you look more closely at the bolsters, you will see the rivets from both sides. I have another 4th Version sitting here, and the inlay rivets are offset. I have a 2nd and 3rd Version that have them centered. I have a few 5th Versions, and I see both conditions, centered and offset. Fun, ain't it?