You could use this tool to just export a PNG, and use that PNG as the sprite, cleaning it up or making adjustments in photoshop or whatever after export. But it seems like the sprites maybe just are the list of parameters used as inputs to the tool.
Ah, you're missing the genius of the Gowers. You see, this game used to run through a browser in the year 2004. A fully 3D experience in internet explorer of all applications. This wasn't a quirky way to make icons for the sake of it, it was memory saving - why store 1000s of sprites when the engine can just render a small image of the drop model? Every strange thing this game does is purely so it could run efficiently in a browser :D
It also saves us Artists a lot of time too, so it has development benefits as well. Of course, wanting to improve the quality of the icons is a little more of a hassle, especially with specific requests like this one - but it can be done :)