Great project and very interesting!

Next one, you might try different distances for the aperture slot from the lens. I think that's one the variables in how the aperture works and how it's effective. Spacing that might change one type of aberation or something. I'm no expert either... I've just seen some of the commercial meniscus lenses and they all seem to have different spacings between the aperture and the glass. Things like the kalosat, kodak portrait, p&s semi-achromatic, etc...