[darinwc]

No, this isn't so. I had a prism changed on my 2n when it was CLAd and my beater OM2, which works perfectly was acquired with some foam degradation on the prism. As it's a bit rough anyway I haven't decided whether to have it sorted yet.

/agree
i have a om2 (dont remember if its the 2 or 2n) and the prism was degraded due to the foam. Still usable, but noticeable black patches in the viewfinder.
Good tip: the OM10 uses the same prism. I replaced the prism in my OM2.. -Doable, but not as easy as I would like. The OM's are seriously packed tight, and the foam was a pain to thoroughly remove.

Somewhere i read that serial numbers past a certain point do not have the foam.
Darin