Before I post more images, I've got to get ok's from the others...
Regarding lens selection, I'm working with 5x7, so I wanted a longer focal length in order to keep the subject as far away as possible. I'm not a fan of wide angle lens portraiture. Normal for 5x7 is about 210mm, so the 300mm lens I found is equivalent to a "long normal", a decent choice for starters...
I also wanted a reasonably fast lens (this is for portraiture, after all), so an aperture of 5.6 or better was my aim point.
I found a 65mm diameter lens that, when mounted gave me a clear aperture of 60mm and a maximum aperture of f5.0. (300mm fl / 60mm dia = f5.0)
Using the same formula I cut a variety of Aperture stops, from f6.3, thru f16.
I liked the f8 aperture best on the ground glass and most of my efforts have been at f8 so far.
On the ground glass F11 looked a bit too snappy and f16 was even sharper (like those old B&J paper weights).
In my limited reading on meniscus lens applications, the concave surface faces forward and the aperture stop is as close to the front of the lens as practical. I've got more information squirreled away somewhere, when I find it I'll post it. Unfortunately, much of it isn't graduate level optics either, but it's a start...