You might find some suitable artwork in FileMaker 2. FM3-4 certainly included extensive button and dialog artwork, in order to provide a flexible set of graphics options to which it was possible to attach a script by which FileMaker would be told to do something, but much of it was by versions 3 and 4 in colour.
The other obvious possibility would be certain applications in the Claris suite: not Works but the more specialist applications like ClarisDraw and ClarisImpact. These had an identical set of graphics libraries, which included (mostly) B&W line art for all sorts of things, including more esoteric stuff such as computer networking; ClarisCAD might have additional resources. Much of the line art used in Claris products right up to the end of the company name should be usable in Hypercard.
The other obvious possibility would be certain applications in the Claris suite: not Works but the more specialist applications like ClarisDraw and ClarisImpact. These had an identical set of graphics libraries, which included (mostly) B&W line art for all sorts of things, including more esoteric stuff such as computer networking; ClarisCAD might have additional resources. Much of the line art used in Claris products right up to the end of the company name should be usable in Hypercard.