Now if only IM would do the "as delivered" orange-maroon-black Milwaukee scheme for those of us who don't want the yellow-borg influence of the late 1950's! That would make my wife a very happy camper!
I think I've found part of what confused them. Amtrak had 5 F7Bs. The F-unit booster they had only two of was the F3B: http://adsl-69-213-240-177.dsl.dytnoh.ameritech.net/amtrak/amtF7B.html http://adsl-69-213-240-177.dsl.dytnoh.ameritech.net/amtrak/amtF7B/amt156.jpg
Those are great looking engines. I am considering purchasing a UP set and then get Kato's Great Northern Empire Builder and have them racing down opposite sides of the layout a la the Columbia River.