Two Snakes from Kazakhstan

I have recently returned from a trip to the Aqtau area of Western Kazakhstan, near the Caspian Sea shore. During this trip I encountered two snakes (well, a snake and a snake slough) that I fail to identify, and I would appreciate any suggestions.

First snake:
a possible Natrix tessellata lacking dark spots or a form of Natrix natrix?

A classic Natrix tessellata found at the same location

The mystery snake:

Second snake, snake slough:

The length was around 90 cm, and the snake appeared very slender, with a small head. It was found in semi-desert surroundings with very sparse vegetation, in a small ravine on clay soil.

According to general distribution, the following species might occur (not mentioning Natrix and Gloydius halys):

Hemorrhois (Coluber) ravergieri

Elaphe dione

Elaphe (quatrolineata) sauromates

I have observed several Elaphe sauromates in the area but none of the other two.