1987, Series 4, Fortress Maximus USA box - whoa!

This is part of item #6 of the Calm before the Storm post.  For some time now, I've been wanting to look for a US boxed Fortress Maximus. At one point, I even debated with myself whether I should get just the US boxed FM or the Jap box C-114 FM. Since as early as 2007, I already had the Jap box C-114 FM MIB, and from then, I was on the look out, on and off, for a US boxed version.