I am not a cryptologist (much) but from what I have read about Kryptos, the K4 section plain text will say something like:
…found at the base of a Berlin Clock…
which will then link in with the whole plan to go looking for something in the grounds of Langley. And there’s a compass rose in the grounds of Langley and that big clock in Berlin.
Thinking backwards. The Samborn guy would have plotted the whole thing backwards.
So, as I am not a cryptologist but a pair of fresh eyes, maybe some of you guys and girls will play around with that phase and crack it. (I hope)