Might the book with the drawings have been something by
Bernard Evslin? I was interested in Greek/Roman/Egyptian mythology in grade school and I remember a lot of his books in the children/YA section.
There was also a rather nice series of coffee-table-type mythology books (about the size of a 15" laptop or so) from each region of the world with black and white illustrations throughout that might be a candidate, which I hope the not-so-local-library still has. I'll have to go check one of these days.