The smallest center I ever used was the Boston Acoustics VRM-C. I believe it will fit your size requirements. It was only about 6" high by about 8" deep; I can't remember the length, possibly more than 17" but check their website to see. It's finished in a really nice dark reddish cherry wood, or in "black ash." I found it to be an excellent center channel that matched well with several different fronts I was using, but they were all dynamic box monitors, not Maggies. Another, even smaller center is the ATC SCM-7, very very dynamic and punchy, but again a dynamic monitor not a 'stat. The size is right, though.
What small center will sound good with Maggie MMGs
I need a small center (7"x17"x10" HWD maximum) to go above my TV in a small cabinet that will match well with Magnepan MMG front speakers. None of the Maggie centers will work in my situation.