This is Robert here, I'd be happy to help with your enormous teapot. 16" is quite a size!
This is a typical Tibetan chang teapot or tea kettle. Sometimes also called a wine server, but probably used for tea more often than wine.
Going by the proportions of the finial and the decoration, I would date this one to the second quarter of the 20th century at a time before the swastika (pierced into the band around the neck of the pot) symbol -which means "ten thousand blessings" in the Buddhist tradition, was forever hijacked by the German Nazi party and is almost never seen in any of the Asian decorative arts post-World War II.
Despite their age, size and decorative complexity, these Tibetan tea kettles have never gained much traction with collectors here in the West where they are viewed as furnishing decorator pieces rather than precious antiquities.
As such, yours would sell at auction in the $120 - $200 range.
It therefore has a full retail/replacement/insurance value of $400.
I hope this is helpful!