I have restored many NY Std. movements and have never seen this particular configuration before. It is the typical 80 beat sweep seconds movement design but is a 60 beat. Defiantly a factory made piece not a later modification. All the other 60 beat movements I have seen are of a different design that make the sweep hand appear to actually "sweep" with movement on both directions of pendulum travel via a unique rocker arrangement with two push pieces. This includes the scarce dollar sign seconds beating model. The normal 80 beat sweep and now this 60 beat move the sweep hand in sort of a stop and start motion with every other swing of the pendulum. Has anyone seen this set up or know of a seconds beating clock with this movement.