In 2004 the game was released as freeware. You can download it on scummvm.org (which is linked here) or on GOG.com. Your Linux distro's software repository probably also has it available.

These releases do not come with the original .exe, though. They only contain the necessary data files to play on ScummVM. To play on DOSBox you need to hunt down the old media (CD or Floppy, either should be fine).

Game Download (Freeware)

mikeSpeedyAdventures

Flight of the Amazon Queen