For what I remember, the MTF curves used to be on the official site
http://www.cosina.co.jp/seihin/voigt...l-m/index.html
but they seem no longer. (I for one don't care!)
And yes, Erwin did test the
humongous 1.2/35
http://www.imx.nl/photosite/japan/voigt1235.html
As far as I understand, he is much less scathing than my reference of the time, the French magazine
Chasseur d'Images.
I am personally extremely pleased with the 1.9/28 (both the object and the pictures taken through it).