Hey! Just made an account simply to respond to this forum.
Im having similar problems to Gabor and was wondering if you could post a pic of your mounting solution Stanley? Also do you add post sharpness?
I was not only wondering about the sharpness of your lens but also how you are pulling focus so well. I'm using this for now, but from a Flickr picture I saw you can simply use a 40.5mm step ring.
At f22, the vignetting is apparent, but its pretty sharp, however now I'm unable to get any kind of shallowness.
(Stretch is not perfect.)