To get a legit copy of the game, you can try looking through GOG.com catalogs. They have a bunch of old games retuned (Dos boxed) for modern Computers. Since this will have the original files, you could then use Scummvm on them.
*EDIT*
Here's a link. It's DRM free so there should be no problems getting the files over to the Amiga...
http://www.gog.com/catalogue?search=Adventure+Soft
