Thanks Michael. I figured they would use the same lens, adding something to create the vignette makes sense as the cheapest way to create the effect with 35mm. Perhaps they do the same thing with the Holga 35 cameras?
I have found meniscus lenses on ebay and the Surplus Shed but they are glass. I also have not found the same FL and diameter.
I'm going to take a chance and order a few DSLR Holga lenses and dismantle the lens. It sounds like they are the same meniscus lenses.