I have collected almost all of the original and classical material pertaining to Greyhawk. I have thousands of minis as well. I have the LG printed 'magazines', too. I just don't have the vast majority of the LG modules.
I had a relative who was one of the artists for some of the original Greyhawk modules. He didn't create too many of the color pieces; mostly B&W. I'm going to see what ever happened to his pieces after he passed away.