I have the headcase and one SVT210AV cab . . . but I lay the cab sideways on top of a 1x15 cab, and put the WA on top of that, for a nice robot-snowman effect. It's secure enough for me and doesn'l look silly (other than the 1x15 being blonde tolex and the 210 and WA being black). But the feet of the headcase do extend a little beyond the edge of the 210 cab - this might be a problem with a vertical 210.
If Chef doesn't have a pic, when I get home tonight I can set it up that way and take one.
By the way, Petersmith, do you find you get enough low-end oomph with just the single 210? I tried it that way and it sounded good (when does the WA ever sound BAD?) but I missed the bottom-end "warm blanket" of the 15 . . . the two cabs play very nicely together.