You'll need to make your own button images 16x16 and 24x24
The code will be near to:
if Sketchup.version.to_i > 13 # no save as before v14 ! save_as_v8_cmd = UI;;Command.new("Save As v8") { model = Sketchup.active_model path = model.path if path.empty? if RUBY_PLATFORM !~ /(darwin)/i # MS Windows path = UI.savepanel( "Save Model As v8 skp...", "*.skp", "SketchUp Files (*.skp)|*.skp;||" ) else # Mac path = UI.savepanel( "Save Model As v8 skp...", "*.skp" ) end unless path.nil? # nil if dialog cancelled model.save( path, Sketchup;;Model;;VERSION_8 ) end else # use current filepath model.save( "", Sketchup;;Model;;VERSION_8 ) end } save_as_v8_cmd.small_icon= "your_icon_name_16.png" save_as_v8_cmd.large_icon= "your_icon_name_24.png" UI.menu("File").add_item save_as_v8_cmd # assume you've created a toolbar ref'd as my_toolbar; my_toolbar.add_item save_as_v8_cmd end