hi chrissyd - to be honest, many of us, like you, would be clueless as to the origins of much of what we find, if we didn't own a small library of books, CDs etc.
It seems necessary to spend time and money acquiring these references sources, but once you have them then positive id's come much easier, although even then not guaranteed - and if these items are acquired over a period of several years then not so painful in laying out a lot of shekels in one go.
glad we've helped with this one. I don't know if the CD for the Sklo Union Database is still available - it was accompanied by the book originally.