I recently found my old World of Greyhawk module. I am having trouble identifying its number. I think the folio is a number 4 but the folio is not in very good shape and I can't tell if the spine is correct for that edition. As for the Gazetteer: what, exactly, are the map symbols on page 4? Mine has population symbols but not the full blown map ones like those on the inside covers of the folio. Also, my gazetteer HAS an ISBN number underneath the 'copyright 1980, TSR Games  all right reserved'. Is this a number 4 or a number 5? And if so, would you like me to try and send you a scanned copy of it as it is one of the blank pictures on that page.
Thanks!

Many thanks to you sir!
Sadly, my module still doesn't fit the descriptionsof the fourth edition. My folio IS a 4th edition; blue script and the wizard TSR logo, but I think my gazetteer is different. I DO have the minifigs flyer but it doesn't say if that was common in the 4th edition; mine DOES list Otus and LaForce on the last page credits for artwork but I have NO symbols on page 4 other than population markers. What else can I do to figure this out or is it fairly common for pieces to be mixed?
Thanks again for your help!

It does help and thank you again. I am the only owner of it and never had more than one so if it is mixed, it happened at the printers. I am not a real collector, just seeking information on value before I sell off most of my stuff so I don't get hosed on price. But it appears that being mixed does nothing to increase or decrease its value. The folio is not very good, still readable but frayed with a few pieces of tape, but the maps, gazetteer and minifig paper are almost perfect, no markings, rips, dog ears or anything, just turning a bit yellow from age around the edges. How does one go about deciding on labeling it as very good, near mint, etc? Or is it best to take multiple pictures and let the buyer decide for themselves? Thanks again for your input!