I have been keeping track of issue covers on the masterworks. Here are the ones with different covers. Title Volume MM HC First MM HC Second MM SC -------------------- --------- -------------- ----------------- --------------- Spider-Man 3 21 23 23 4 31 38 33 5 41 50 50 7 K.S.A. 5 NA S.S. 2 Hulk 2 T.A. 60 T.A. 77 T.A. 77 Fantastic Four 2 11 12 12 3 K.S.A. 1 29 29 5 K.S.A. 3 48 49 7 66 NA 61 Avengers 2 11 12 12 3 21 21 23 Thor 2 101 108 108 Daredevil 3 27 NA 23 Sub-Mariner 1 T.A. 70 NA T.A. 76 Silver Surfer 2 6 11 11 X-Men (old) 2 11 12 12 X-Men (new) 3 111 112 115 Human Torch 1 T.S. 101 NA T.S. 107 Some of the covers have been changed twice. I hope this helps out.