Roger,
Impressive work and a steady hand!
I love this line of lenses. I have one "descendant", the Super Multicoated Coated Takamar 135mm f2.5, with 8 leaves in the diaphragm as opposed to the 9 in your lens. I use mine on the Sony A7R with an helical focus adapter allowing for macro work.
Are these full frame?
Admittedly, the XE II is already superb with a1.5 X multiplication factor to be equivalent to just10 degree of view, Is that all you're using to get the great magnification here?
Asher