[special-K]

You show the same thing I showed. I'm trying hard to see how you get out of that the 68/69 knobs are red plastic. It's the '70s that had red plastic and their part # is the same as the blue 71/72s. GM parts is not a restoration business, it's a replacement part business. They will supercede a part with one that works if the original design is depleted from stock. If the 68/69 hub assemblies listed are red plastic with chrome retainer rings, it could be that GM had Spicer make a batch so they could continue providing replacement parts to comply with the law that requires mfgrs to provide replacement parts for 10 years. And since Spicer changed the design, they would have made new assemblies to work with the closed knuckle Dana44s in that design. I do know, from my experience of dealing with and owning these 4wds, that from the factory the '69-back K/10s came from the factory with the metal Spicer hubs. I have never owned a '69 blazer and never been well acquainted with one, I can say that. I believe it could be possible that the Warn (GM misprint) semi auto hubs are what came on '69-only Blazers and those would be Warn's Loc-O-Matics. They would interchange with the K/10 hubs as a replacement. Those came bronze with red painted in the recessed area. The most original '69 Blazer pictures I have found show the knobs as yellowish, certainly not red, and they aren't the design as the plastic ones. My guess is those are the Warns with the red paint gone

As far as GM superceding a newer design part in place of the original design due to depletion of stock, Have had experienced that many times. I remember I got all excited, in the early-80s when I began ordering still available 67-72 parts, when the parts guy found the 69-72 steering wheels were still available but only in black. I ordered one, it came in, and it was a '73 style wheel. I've had it happen over and over again. I have bought front wheel bearings for a '71 K/20, way back then, that had "Made In Japan" stamped into the race rim. I am willing to accept that somehow I never saw or owned 68/69 that came from the factory with plastic hubs before if I see proof. But in my years of dealing with these 4wds parts I have had more guys than I can count asking if I had the original all metal Spicer hubs for their pre-70 K/10s