Thanks so much redler! That's totally it! I found a number of photos of the book on flickr (http://www.flickr.com/photos/erice/sets/72157625355578461/) and they really brought me back to my childhood. I had the first two as listed here: http://www.khantazi.org/Rec/TTABooks/TTABooks.html

I'll have to see if I can pick up the whole series. Thanks again!