I have never heard any numbers but I would guess that when new there were more E-3s made than 30s. I would also speculate that there are more tractors that started life as an E-3 being converted to 30s than the other way around. Just my 2cents worth!
Tony Is right I know when e'3's came into grandpa's dealership a lot of people didn't want a orange tractor so the dealer painted it red but always kept the co-op center strip. Most of the 30's I have hauled home over the years were that way.