Note: I said a model 27 would be a tossup--not a Registered Magnum. Now, of course, there is this whole "French" thing, which obviously takes away from the MR-73, but I take solace that Manhurin was actually located in Alsace, not French, France (yeah, it's kind of grasping at straws, but I'll take what I can get). And, as much as I like Smith's, what S&W can fire over 150, full-house, 158 grain rounds per day for year after year (even if that means only around 200 days a year because of all the French holidays and vacation days)? Some folks say that in their opinion the MR-73 was the best combat revolver ever made.
So yeah--M 27 or MR-73 is a toss up for me, with "both" the preferred answer and "neither" the present, and probably continuing, reality.