Ulysses19: what 150mm do you have right now and how much coverage do you want/need ?

A modern 150mm Symar or Sironar will give you about 4cm of movement, if you want more you are looking at W or XL types that are very pricy.
And all of them come with their own shutters ofcourse.

Just swapping lensparts around looks and sounds easy, but reality is diferent.