A very
nice sample from 1944-45. Very clean lines and this is a summer
version - no fur. The leather on the inside is very soft and this
would be a comfortable helmet to wear. The flaps over the ears held
the earphones in place.
These look like the predecessors to the ShL/Z-50 series. They use the first oxygen mask (copy of the U.S. MA-2) made by the Soviets. These specimens are valuable to a collector since they are very rare (including the masks). The mask in the second picture is the transition mask between the mask in the KM-24 picture. The KM-24 picture mask is the direct copy of the U.S. mask. The other mask is the transition mask that later developed into the KM-16. The top and bottom helmets were meant to be used with the bottom mask (only a single hook). The top mask would have been used with the WWII version leather helmet.
Purchaser tips:
WWII was a long a time ago and any helmet is now over 55 years old. These are still fairly plentiful and consequently, fairly inexpensive. $50 - $75 will get you one and if you are willing to part with $100, you should be able to get one that looks like new.