Is there any update to this? I heard it thru the 'vine' that DVD copies have been given to the NSS. Is this true?
I'm not in the loop on this, but a quick check of the NSS A/V Library shows "Schoolhouse Cave For Fun" (Explorers Club of Pittsburgh, 1963) as DVD23. Don't know how long it's been there, but the number would indicate it's one of the first DVDs added. It's not in the Video (VHS) Catalog, so somebody must have provided a video or film copy -- hopefully a pretty good one...
Dave Socky is in charge of the Library, and so has the master copy and can make you more, or you can check out the library copy and make your own.
OTOH, Dave is also involved with the Germany Valley Karst Survey, and so may well have already provided copies to the owners. Why not ask him at email@example.com.