This briefcase probably was a farewell gift when Dorl moved away from BC, Canada, to spend part of the year of 1970 at Austria. The written material is childish and playful, but in short time at the Höhere Schule he established his reputation as beeing very good at math. He didn’t finish with Matura but went back to Vancouver to enroll at UBC and back again, this time to Berlin. He finally passed Studienkolleg and was able to matriculate at FU in Physics. This was in 1972, at the age of 19.
Finally the mystery has been solved: where the heck went the vanished chess piece?!
The calendar, included in the brief case, is most sophisticated, methinks.
Corrugated Box, Containing ‘Survivals’
see entry: Tuesday, 4 July, scroll down to: Three “survival” kits
It was probably in 2009 when Dorl emptied his pockets and filed everything away.