Nice camera. Congratulations.
I'm building a 16x20 as well and it is almost finished (a little paint and velvet and it is ready).
Good luck with your pictures.
Wow. What lens are you using to cover a 16x20 piece of film?
I'm curious. As it isn't in the build photos, did you attach it to the back of the lens or to the front like a typical filter? Also, where did you find a negative diopter lens of such a diameter?
Thanks. I've ordered a couple of negative f.l. meniscus lenses to experiment.