I find this very neat as I have done the same in the past. I have always wondered if the T205's are part of the T206 series. Kinda like a parallel set that may have not been to popular. This may explain why all of the T205's are 400 series only. I believe (I am sure Ted will correct me if wrong) that there were some White border cards printed after T205's. The T206 460 subject right?

Maybe Burdick was lazy? (Just Joking but it is human nature sometimes) I have wondered that maybe he had sets of the cards there and classified the T205's first because it was the smallest and easiest.