Extra standard petals are commonplace, and extra wings are not unusual. Sweet Peas occasionally develop extra half-keel petals, always outside the keel.
It could be that the keels throughout the pea family
evolved by the fusion of two aboriginal petals, and these odd half-keels we see may tend to support this view.
Extra standards are usually like those in the two pictures above, similar in height but of various widths. Very rarely, the
standards are perfectly formed and overlap exactly, wheras ill-matched smaller standards are quite often seen. In all cases, it is very likely that an extra standard in the growing bud will get caught by the developing keel - very ugly.