Reading the great website of LondonJazzCollector  (here), a site with all types of fantastic and interesting information about jazz vinyl and the collection of same, I came across some interesting information concerning labels and ways to date your Riverside album.  My copy has conflicting information.  According to the knowledgeable folks, albums after 12-272 had the small label, where the deep groove runs through the recording symbol gray box.  As you can see, my copy didn’t know that.  Any ideas?