A year after the 1st Chan box set, german distributor "Kochmedia" released a 2nd.
Still in chronological order they included Shanghai, Secret, Circus and Race Track (all dubbed) with the extras from the Fox dvds.
Another distributor brought the dubbed movies The Trap, Dangerous Money and Dark Alibi as single dvds. For this year they announced to release 2 more Toler/Monograms: Scarlet Clue and Chinese Ring, but it seems unlikely because there are not known to be dubbed. Wait and see ...
This is wonderful news! I know of no other German dubbed versions of Charlie Chan films. Perhaps you might take a look on eBay or other internet sources?