Cool find, I was surprised to still see icons for eMacs, iMac G4, G5, some Power Macs (MDD, Quicksilver, G5) in Mavericks. I'm surprised they are still there, but I'm glad too I like the iMac G4 icon, I had a iMac G4 for just over a week, wish I could have another - and I will eventually! Finder -> Go -> Go to Folder, then paste: /System/Library/CoreServices/ A finder window will open, find "CoreTypes.bundle" then right click "Show Package Contents." Now go to Contents/Resources/ and all the icons will be in there. They will be .icns files, and use a program such as FastIcns to save them as PNG files for Photoshop or whatever.