Bachmann UP 484s

[Car Bud]

 I have returned to the forum today after a long absence and after running back to a February entry about the Overland Limited Freight set with the old and new 484 locos including some pics of both locos. I have one of each of the ATSF Northern clone and NYC Niagara clone of A UP "806". ( I converted the old ATSF 806 to a fictional CNR 6100 Class 484 by adding side skirts and light green paint)
Question: Why did Bachmann not produce either a correct version of old 806 or later 800 class UP loco such as the 844 FEF( by Walther's) that was also mentioned in that entry? Was it that Walther's had a design reproduction patend of the FEF UP loco? What was the reason for cloning other Bachman Loco's ( incidentally, The Niagara clone does resemble the original 806 more than the ATSF Northern. Which brings me to another question: Did Bachmann clone the Niagara 806 from an original Bachmann NYC Niagara? -(-Which I have never seen) Where did it come from? Hope this will not confuse anyone reading this. Thanks . Carbud