I've been looking at M50 photos from a bunch of sources: Dr. Rob's book, Tom Gannon's book, the Verlinden book, Toadman's CD of the Littlefield tank, and more. It seems that the castings for the rear bustle had some subtle shape differences, with the profile on some seeming to be more rounded at the back and others showing a more pronounced ">" shape back there. How many foundries made these parts? Were the early ones from France slightly different from later ones presumably cast in Israel?

Also, just to be sure I'm grasping the subtleties of the shape, the bustle is a couple of inches wider than the shelf it sits on, yes? And where the front of the bustle casting meets the turret casting, on top, there is a compound curve? That is, the bustle casting curves gently downward at the front, and slightly inward as well at the rounded corners?

Trying to scratchbuild one, naturally....