I can attest to some of the antique equipment - much of which has no documentation and one-of-a-kind. I fixed that which could be fixed and recreated other equipment.
I dont think that aging equipment will be the problem. I do think that its highly probably that some NASA career "manager" had the tapes in a file cabinet for 20-30 years, then threw them away when he retired.
The amount of records that NASA keeps has got to be incredible. Since the invention of the camera and motion picture technology, mankind has gotten to where we record everything. However, we record it in the most impermanent methods imaginable. Add to that, we don't seem to have any idea what's important, anymore. Even something as incredible as the moon landing becomes mundane to the people working space travel every day. I hope they find it.
Or they ended up in his attic. I predict they'll show up on the "Antiques Road Show" in a few years.
I can see that happening, or the more likely scenario is that after he retired, the folks who went in to clean out his office went, "Hey Charlie, what do we do with all these old tapes, any idea what they are?" Charlie: "Hell, I dunno, but if no one's used them in 20 years, they must not be important, take 'em out to the dumpster."
Yeah, right. I've got a bridge for sale...
Perhaps getting a local dive club to scour the bottom of Greenbelt Pond (Lake?) might be a consideration?
I could just picture some guys attempting curling with film reels on a lazy winter afternoon.