Mike, firstly, must thank you for pointing at the right direction in reading some of the artical about MTF, that something good to know. I know more about it (can't say that I understand it, guess with time will understand more).
I do agree with you that firstly produceing the standard white light will be technically difficult{impossible). Measuring these white light, and produce some readable table will be nightmare! I don't know if this is true or not, but the more we know, the more lost it seems to be (what the acient chinese use to say).
So what I am suggesting is more simple (don't know if it will work though), what we need to do is to get the computer and print a "standard" color referece (with all 64 bit or 98 bit) colour. Use the lens to take photo of the print (with a standard film), scan the film with a standard film scaner, and read it with a computer and see how many different colour captured by the lens. Repeat for a few times and get the mean. Collect data from different brand of lenses and compare. Will it works? All of these hardware are available, it is the colour counting software I am worry about (it may take forever to read with 64 bit colour!)
Using a DSLR may be another option, however, mounting all the lenses will be technically very chanlenging, and may cost you a lot of money.
Robert, there is no doult in the past Zeiss or leica produce the best lenses! However, and IMHO it true, according to the MTF, the other brand are catching up. looking at the MTF of Canon, the mean of their score in MTF chart are very close compare to CZ or Leica (sometime better). So if CZ/Leica's lenses do offer something extra, I think it is important that we could describe it, and let other to know! By using subjective word such as great, stunning, fabulous to describe it is simpily not enough! or otherwise, in the very near future (comming very fast! things do change fast these day!), more people will just use MTF to judge the lenses quilities and we will have no more CZ/Leica!