Hello Greg,
Always welcome more discussion on Goodwin's issues. The OJ book covers seven variations of the metamorphic trade card. An 8th variant with no corrections was a late add but doesn't seem to be too difficult as a few of us that collect the variations have obtained them, sometimes in duplicate. So you have what I'd consider the 6th & 8th variation of 8 possible. Most of the variations are pretty similar in difficulty with a few that surface less frequently.
The OJ book provides an image of each variant. You have a good start, six more to go