Amazing how some vision-lacking person in a company can unilaterally choose to discard a company's history.
I see the same thing at universities. It's a rare person who cares about preserving history, records of past activities, or documents related to major projects.
Glad to see that Gibson recognized they were missing the records and is trying to retrieve them. Perhaps some Gibson fan stuck them in his garage when he got the chance. Or maybe they're in a landfill.