Chakra (Wheel/Discuss) and Shankha (Conch Shell) are symbols of Vaishnavism. Vishnu is normally seen holding them in his hands. One such example on this site is Vishnu. Here the implements are mounted on their own and are meant for worship. This worship of implements is a part of prescribed rituals.
The bronzes, such as these, would have been kept in the inner sanctum next to or at the base of the main deity. In this case, considering their sizes they may have been used in private worship. Obviously, they are not a pair (Differing height, design and base) and are published together as that is how they arrived, but with a description ‘they are flowers’.
It is not often you see older pieces like this in the market. The flamboyance of the design, especially the Shankha (Conch shell), on the left, is to be noted. The loops at the back of Chakra are meant for placing flowers.
Most likely these are from Karnataka/Northern Karnataka. But definitely from South India. The tassels or flame-like structure at the outer edge suggest they are of a later period. These may not be any earlier than the nineteenth century. The heights of Chakra and Shankha is 13 cm and 10.5 cm respectively.
Some of the observations above are from AK.