FS early Brass Kodak/Bausch and Lomb 8 and 14" convertible
I used this years ago and it covered 4x5 with no problem.
I measured the focus image at about 8" and 14" with front cel removed.
Has a very large flange. It is large enough to friction fit in a wood hole.
B, T and I settings. "I" seems to be about 1 /25th
Piston type air release works. Just ad a tube and bulb.