Too many Westminster chimes ?

I have a Junghans oak wall clock I think dated approximately 1920. It is a 3/4 Westminster and chimes the tune too many times. The hourly number chime is OK it is the melody that is repeated too many times. For example on the quarter hour instead of the four note melody it repeats it and plays a 16 note one then at half past the hour instead of an eight note o e it plays a 24 note one!!!
Can anyone help and advise what we could try to correct this. It's not a valuable clock so not worth taking to a horologist. We have a very limited knowledge of the mechanics of the workings.
We would be grateful for any advise.
Thanks,
Sue