I have several of the lug casings pictured below. The two in the first picture are marked Premier inside. The four in the second and third pictures on the right are similar to Premier but not quite the same. They either have no markings inside (bottom left) or letter/number combinations like "RD 56" (top left and middle left - looks like someone cut the ends off of the style above) and "RD843756 436/20" (right).
Does anyone recognize any of the four that are not marked Premier? I have looked through some Premier, Olympic and Beverley catalogs with no luck. I have seen some Premier lugs on UK eBay that had "RD" or "RD (followed by numbers)" inside, so I am assuming that those that have similar markings are Premier. It seems that there were many variations through the years.
Thanks