I dunno why the robot devil specified "solid" gold-- the original song just said gold. You can make violins out of metal, so theoretically a gold one could work.
If you rest it on your shoulder and are gentle when tensioning the strings, it can probably work, but don't go too aggressive on the strings or they'll probably snap (if gold) or bend the tensioners.
I'm going with "plausible" but totally impractical.
I thought people usually just did a gold coating around a more reasonable material. In this case, your fiddle would still be wood, but it would have a gold finish to look pretty.