Series 500 plossl?

I own a 40mm Series 500 Plossl that came with the used scope I purchased. Who makes or made the Series 500? Were they sold through a big scope company or are they an otherwise no-name import? Are they comparable to any ordinary plossl (as opposed to super plossl)? No help on the internet tracking this down.

I have a series 500 made by Meade if that helps. It does not seem to be a super plossl and has a small field of view at least with the 30mm I have. But it is sharp to the edges, most likly due to the narrow field.

I bought a Series 500 10mm plossl from Gary Hand at Hands On Optics; his "GTO" Plossls are no longer labeled "series 500", it seems, but were at one time.

I don't really know, but I'd bet they were sourced from the same place as the Meade "series 500" Gary Davis is referring to.

They're a pretty ordinary generic plossl, but mine was well worth the super-cheap asking price. I bought one as an upgrade from cheap Meade MA/MH eyepieces, and it was big improvement there. The FOV is slightly narrower than other inexpensive plossls, but it's otherwise decent. I've "retired" mine since then in light of later purchases.