Interestingly the very early issues were only available through the Woolworths stores in Great Britain. From 1949-1954 the annuals were published by TV Boardman with dust-jackets. From 1955-1957 they were published by Popular Press. From then on they were published by Dean. The annuals from 1953-1958 were numbered 4 to 9 on the cover. The 1961 annual had a number 12 on the cover. The last annual (#13) was called Buffalo Bill True West Annual.
What makes these great annuals very collectible is the wonderful colour artwork and covers by Denis McLoughlin. And you can pick them up as a bit of a bargain it seems to me.
Note: some PR issues may have no value. Selected issues in FN, VF or VF/NM may not exist in some titles.