Agent H,hi.I can't follow the links you've provided(my internet speed+the funk factor often inseparable from russian-related sources).
If you're wondering about this specific alloy,У7(as well as У8,У10,У10А,У12,and on and on),then it's just a "simple" Carbon steel,with 70+%C,analogous to AISI 1070,1075,1084,et c.
The russian code У stands for Углерод,which is Carbon;if other alloying elements were present they'd also be indicated by their letters;so,U7= AISI 10xx series alloys.
The handle on these axes was most commonly birch(thus the volume inside the eye,it developed like that initially because there's not too much BUT birch available,in the more northern,i.e. forested,regions).
The haft was often made out of the jug-butt part,using the beginning of the root flare...(meself,i'm fairly cynical of the practicality of this,as i find the grain in the root be coarser,and the wood on the softer side,but arguing with "traditionalists" simply ain't worth it....).
Because these people had access to not much of anything but birch,they developed this loyalty to it,and began justifying it by saying it's the Only Way(of course).And the softness of birch,it's low density,began to be worshipped culturally(i'm speaking Very generally here)as an ultimate handling wood for it's shock-absorbtion(true to an extent,stands to reason...).
The shape of the "traditional" haft always held little aesthetic appeal to me personally,but here's a resource where you can see many examples of such,
Here's (a rare)one that is more or less appealing:
http://rusknife.com/topic/13397-есть-железо-нет-дерева/page-12#entry629753, the post # 332
And here is a long thread on this type made by the Zlatoust factory,one of the oldest,most well-known makers:
http://rusknife.com/topic/12708-топоры-зик-он-же-згз-советского-периода/page-19#entry630230
Again,i'm not a great fan of these axes,and lack the insight(tried and failed to id your specific stamp,it could be Zlatoust,not sure...ЗиК stands for the abbreviation of Zlatoust instruments Factory).
But hope all that helps in your search....
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