But what is the statistical likelihood that they "all" have been trashed? It gets me to thinking about a much older and less useful computer, which still crops up for sale now and then and now fetches over $100,000 -- the Apple I. And we know just how few of those that were made. And again, they were much older and less useful than say an SE/30, the latter of which was manufactured in greater numbers. So I guess the real question would be, just how many of those SE/30 socket upgrades were made? If they were built outside the USA, my guess is that the manufacturer had a minimum build of 500pcs or perhaps 1000pcs. Unless you own the foreign factory, most factories simply will not build something in quantities less than that. Even if there were only 200 made, statistically speaking, I still feel it is likely that at least a couple are floating around out there, unbeknownst to their owners.
Suffice it to say, when my SE/30 has one of those socketed upgrades AND a grayscale adapter installed (along with my MacCon PDS Ethernet card, of course), my vintage Mac computing life will be complete. "You may say I'm a dreamer. But I'm not the only one..."