Pair of old wrought iron and brass tracks from the 17th century

Pair of old wrought iron and brass caterpillars from the late 17th century, they are with a nice iron work and decoration of a shell with hooks on a rotating upright. 
Note on one of the two models the brass part is a little damaged, they are very robust and sturdy. 
Dimensions width 30/31 cm height 12.5/59 cm depth 53/59 cm