Are you sure that the Canon Macrophoto lenses are multicoated? I'll have to check mine.
The Leitz Photars are also very good and I will have to compare the Canon Macrophoto lenses to my Leitz 25mm f2.5 Photar. You can also try and get one of the discontinued Schneider M Componon Lenses or the 2 Rodenstock - f4.0 75mm 1X Apo Rodagon D or the f4.5 2X 75mm Apo Rodagon D lenses. These 2 lenses are designed for copy work and high magnification for 6X6 and 6X7 cameras. I will have to compare these to the other lenses as well. They are supposed to be superb performers.