1) He showed me 16 billion(ish) covers, so not sure of all the variations.
Most of the time was spent with me saying,
"OOHHHH will you sell me that? Please? Purty Please?"
and Eric kindly explaining it took him 10 years to find it and no, I don't think I want to sell it...

and

B) Who would EVER mix regular covers with features???
We're not animals here!!!!!