I'm pretty sure (99.9%) that the "JOHN DEERE" block lettering is the same as used on the 50 and 80 carts.
As for the "30" decal, either do a search on eBay for tractor number decals where you can often find a sheet of various numerals in the green and yellow colors, or do what others have done and by the "80" decal and trim the 8 into a 3.