How are the four elements grouped in a Plossl

I have disassembled a few orthos to blacken the edges for better contrast. It did make a noticeable difference. I have an older Park 25mm Plossl (non gs) that has some sort of debris in between the elements. I would like to disassemble it. The orthos really were no problem mainly because there was just a spacer in between the two elements . My question is, with four total elements in two groups of two, are these groups of two, cemented with a spacer in between the two groups, or are all four elements separated by spacers. From the diagrams I have seen it looks like they are cemented together in two groups and separated by one spacer.

I just wanted to know what to expect, after unscrewing the retainer ring and start removing the elements.

I am aware that it is not advised to attempt to disassemble an eyepiece. I am doing this as a "can I do it project" It is not worth it to send it to the factory. Whatever is in between the elements (mold) makes the eyepiece pretty much useless, so nothing to loose and perhaps a little knowledge to gain...

Gary, a quick search on Google will provide plenty of diagrams to help you.

Plössls are typically made with two cemented doublets -- just two lenses. Of course if you lose track of the orientation, there are only four different ways to reassemble everything.

Plossls, typically actually Symmetricals, are these days two identical doublets. Each doublet is cemented together. The two doublets are separated by a single spacer. Today's typical Plossl is 4 elements (there are some called Super Plossls that may have 5 elements). For the 4 element, 2 group variety, each doublet is typically plano-convex, so one side is flat and the other curved outward. The orientation of the two doublets is always having the two convex surfaces facing inward, and the two plano surfaces facing outward. So the top of the eye lens is a plano surface and the the bottom of field lens is also the plano surface.

A few varieties of these Symmetricals (again called Plossls these days) have instead of a plano surface on each double, have a slightly concave surface. You see this on TV's (which is their patent version), as well as a few others like the Sterling (Long Perng) Plossls. But regardless of variety, the convex surface of each doublet faces inward when you reassemble.

http://lib.store.yahoo.net/lib/opticsplanet/plossl-eyepiece.jpg