Hi guys looking for answers to a couple questions I have. What year and or serial number did Deere change its decals on the 6030, 7020, 7520 tractors? I have seen them with both styles and wondered if the "72 models had the "4020" style and at "73 they changed or is there a specific serial number they switched to the 30 series style. I am collecting the new gen 20 series and would like to get these models with the 20 series style decals and be appropriate for the tractor. I just bought a 7520 sunday that according to the serial number list on this site is a "72 but it has the 30 series style decal. It has been repainted did it just get updated to the new? Thanks for any help.