Primarily Petroliana Shop Talk Forums Shop Talk Petroliana Forums General Petroliana Discussion Is there a book on sign rarity...Rated 1-10?

After three weeks, the auction company finally sent my Mobilgas tanker truck sign. Is it a keeper or am i likely to run across one of these again? I figured each trunk delivered to atleast 30 stations, each having two or more pumps with two pump plates each. That would be 120 pump plates for every one truck sign. Wow, that makes my brain hurt! Would that be even close? LOL.... Anyway, I read somewhere that there was a book that rated signs 1 thur 10 for rarity. Have you heard of it? Thanks,Owen