Gerbera daisy

I have had this plant in this container for a few years and have noticed that over time both the flowers and foliage have dwarfed to some degree.  The container is dear to me as it belonged to my father.  I am not sure of its origin but I know it was purchased by him in the early 1950's....I would very much appreciate any additional information about it if someone on the forum would know.  Many thanks.

Regards,  Tom