Hi Gregm. I have always had something of a sweet spot for the 63s, and I must admit, have not liked as many Maggies as I have disliked.
When my wife first met me I brought her home and there, one third across the lounge, stood a pair of 63s. Somehow we got past that point in our relationship, at least in part because she loved the music those 63s made. And you are absolutely right, I was able to make them sound pretty good even when they had to find a place somewhat closer to the wall.
That was a long time ago and I drove them with an old Perreaux 100W Class A amp, of which only 25 were made, and mine had upgraded passive components. It was about the sweetest and smoothest amp I ever heard, but a little dark and lacking in dynamics. But the midrange was "to die for" and the marriage with the Quads was really something on voices and chamber music.