Class A Push Pull - output transformer specs

[Wavelength]

Cool design, love the simplicity of it. The driver is close to the center making the most of all it's SPL.
It'd be fun to make a work-alike. I've built a number of horns and their TL cousins over the years..

DV,
Attached is the files for the curve I calculated it out with. I did this so long ago I can't seem to find the drawings for it.