Looks like bunches on ebay, so I'll have to adjust values in the new edition of the Washington book (now, when that will be, is anyone's guess! ). Also, the fact that they used them for years, even after the "official" name change, means plenty got out. I'd probably assign a "B" value to all in the set, unless I see any evidence to the contrary, as I believe many of each version are now available. I'd say the 2.50 is now probably the "rarest" of the set, since there weren't many of those to begin with.