The first of these, MG50039, fits in with the Mercury covers of the 50s – George Maas drawings and designs. Then all of a sudden we are in the 1960s. Various designers, various artists, and a completely different design feel. The last of them says design George Maas on the back, from the period when he was just designing but not drawing. It does not appear to me that there is an earlier MG50047 cover that this one replaced, it just seems they stopped using MG50000 numbers for a ten year period. But the MG50070 series ones are from the 50s.
If anyone can identify any of the artists on these covers, please do.
Sorry about mis-numbering them as ML instead of MG.