Well, now I am a bit disappointed with the whole exercise around this 200mm FD lens..
After mounting the lever to control the diaphragm, I expected the red halo around the overexposed stars (obvious on frame above, cropped from corner) would go away.. but it did not.
Something like this was never reported for this lens, or I was not aware of this. Interestingly, similar halo I observed on images taken with 50mm f/1.4 at full aperture, but the effect disappeared completely at f/4 - f/5.6 (OK, I am comparing apples and oranges here, I know..)
It seems this particular lens is a dud.. with too much chromatic aberration
Well.. such is life.