I agree with everyone else. I have two copies of Jack's 2nd pump book - one in the house and one in my truck. I also have both PCM guides (old and new); and I have the new Globe CD loaded on my computer, iPad, and iPhone, so I have it with me all of the time. Also, talk and visit with petro collectors whenever you can; there are quite a few very knowledgeable people in Michigan alone.
Good luck, in the hunt!!
Always looking for Standard Oil of Indiana, or any globes!