Thanks for the helpful photos which have now been forwarded to me.
This is indeed a curiosity and quite a whimsical creation with all its 12 babies.
The decoration of little circles and the fern-like lappet band is certainly typical of Chinese, or more specifically, southeast Asian decoration, of the sort seen in the Burmese or Thai decorative arts. The scrolling foliate pattern is a typical Burmese decorative motif known as maw-pan.
In the Asian tradition the turtle or tortoise represents strength, endurance and longevity. It's also become a highly popular symbol in the practice of feng shui where it is often depicted on a pile of cash coins and with a number of its babies around it or on its back, and believed to be attributed with the power to attract wealth and to advance ones career.
The small circle motifs on yours are most likely coin symbols in miniature and, as such, I would say this is an early version of a tortoise adapted and decorated for feng shui use, probably dating to the early 20th century.
As for value, it is certainly a large and decorative figural group and would certainly appeal to tortoise/turtle collectors, a significant force independent from the Asian feng shui market. So, if you were to see this set for sale in an antique store, it would have a full retail value of at least $300.
This is also the replacement value for insurance purposes.
I do hope this helps!
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