What I discovered amongst all of those stands, is that the CB350F stand differs fro the CB400F because the extension that you put your foot onto, on the 350F is a lot longer than the 400F.
What I also just realised is that the stand off my mate Jim's CB250K4 differed from all of my CB250 K0, K1 & K2 stands but the parts book shown no change. The sections that contact the frame on his K4 stand are much wider to spread the load presumably .. same as on the CB250/CB360G5.