Antique 17th Century Russian Muscovite With Camail Of Chain Mail

 Rare antique 17th century Russian Muscovite helmet in the eastern style. A hemispherical skull formed of a one hand-forged steel plate and a camail of chain mail constructed of round wedge riveted rings attached to the helmet by wire.
Most 16th and 17th-century Russian arms and armor, including helmets, were made on the pattern of Turkish, Persian, and other Islamic arms and armor, but with some diversity. This particular helmet is made in the style of a 17th-century Islamic helmet; however, there are differences;
1. the shape of the skull is slightly different than Islamic helmets 
2. is made of hand-forged high carbon steel (cracks in the skull characteristic of high carbon steel)
3. the steel plate from which the helmet is formed is much thicker than on Islamic helmets
4. the helmet's surface is completely plain devoid of any ornaments in engraving, etching, chiseling, or gold/silver inlaid decorations characteristic for Islamic helmets
 
I never had a helmet like this over my 50 years of experience from trading in antique Arms and Armour.
 
REFERENCES: There are several examples of similar type Russian Muscovite helmets preserved in Russian museums. This type of helmets is cataloged under different names such as:
Мисюрка (Misyurka)
Шишак(Shishak)
Шапка железная (Iron cap)
Шело́м (Shelom).
Many similar examples of 16th -17th-century Russian helmets can be seen on web pages: Muscovite Armor — Московитские Доспехи
where photos of these helmets are posted together with 16th-17th century Russian Muscovite armor.
Please see the link below:
https://muscovitearmor.wordpress.com/page/8/
CONDITION: Showing age and usage, slightly pitted overall, dents with a hole, and minor cracks from combat. There are small punched holes on the top of the helmet and the sides, so there is a possibility that the helmet once had some hardware attached to the skull. 
All of this can be an aspect of an old combat helmet, considering that its age is over 300 years old.
Measured approximately:
Height from the top of the helmet to the bottom of the mail: 33 cm (20 inches)
Height from the top of the helmet to the bottom edge of the skull: 13.5 cm (20 inches)
Diameter: 19.4 cm (7 5/8 in)
Weight: 1.265 kg (2.789 lb)