I am late to this thread. I will start by noting that I am in the "you build them to run them" camp. I have an informal "catch and release" policy, that goes something like this: If I have a model that is "ready to run" that has been doing nothing but sitting in a box for a long time, then I find a new home for it where it might get some run time -- or at least put on display. It's not a rigid policy but I have sold quite a few number of operational locomotives simply because I had lost interest in running them. Part of the motivation is to slow the growth of the pile. It's helped, but I still have too many models.
As it is, most of my doorstops diesels are not ready to run. Since Bob posted a lot of E7s, I will add this one:
As has been noted, the all-cast E7 was made by Exacta (after, I believe, their purchase by Central Lines). There were two versions. The first has a notable flaw: The slanted front vent, as seen in this B&O versions, posted previously by Bob:
As an aside, I agree with Bob and Pete that there is some charm to this model. I am not so sure the finish can be cleaned up to the point of reasonable satisfaction, but it's worth taking a look at to see what we're up against.
At any rate, Exacta eventually fixed the flaw, as seen in the first photo. These are my favorite doorstop E7s. I imagine the castings are Adams and Son, but only the truck sideframes are so marked, and the roof and sides are not found on any other A&S based E7, specifically the Siebers Bros. or Fernando Valley versions. My guess is that Exacta provided their own patterns and had an exclusive, which Lindsey Adams honored.