EVERYTHING in his “collection” is being (slowly or quickly) degraded/destroyed, merely by his colossal ineptitude.
A perfect example of that: a vacuum-tube tester which he destroyed by allowing it to become rusty, and encrusted in rodent-droppings (because it was improperly stored).
His dumb-assery destroyed that vacuum-tube tester every bit as much as if he had taken an axe, and deliberately smashed it to bits.
Another genius instance of Karl being inept was the fact that he “lost” one of his Yaesu Vx-7s in a pile of random, moldering scrap. Predictably, the stupid fuck had neglected to remove the AA batteries, which had leaked, and damaged the Vx-7. He claimed that it was “probably” repairable, but a conscientious person would never have “misplaced” the thing that way, in the first place.
So that’s basically the primary issue: his compulsive hoarding (in combination with his utter ineptitude) neccesarily means that pretty much everything he has “collected” has probably gone to shit, after several decades of neglect/mishandling.
Like, for example, the mid-1950s ARRL handbook which “just happened to end up” on a shelf-unit in his bathroom — “because that’s where he had shelf-space”.
The fact that it is moldy indicates that a significant amount of other printed material is probably also similarly destroyed. (Like, for example, several boxes of books on electronics and computer science and suchlike which he “liberated” from a former workplace, crammed haphazardly into cardboard boxes, and never bothered to examine again for over ten years — even though he knew about the leak in the garage roof.
Quite simply, even if there was something of value in the hoard, chances are that it is most likely moldy, corroded, covered in rat droppings, etc.
Way to destroy what you claim to value, dumb-ass.