I have some I believe to be from the 51/52 but nowhere near a complete set, did some fairly intensive searches attempting to find checklists for those years or even definitive examples to match up styles but was unsuccessful. From what I read these sets were something that was dropped from collecting catalogs as the years and existing sets progressed unfortunately. I'll post another thread with scans of the ones I believe to be from that period a little later and hopefully we can at least match ours up.