We'll never know the reason for the long stock. But the charging handle was due to the ease of production.
As stated earlier it was a simpler design than other SKS's, but it is NOT as ergonomic. Every time I charge the carrier on my Albanian I feel like my finger will slip off, I prefer the other, normal style.
The longer stock does give the gun a shorter feel, at least to me, almost a psychological close quarters advantage, but more than likely not the reason.
The magazine is differently shaped but gives it no advantage.
Some spare parts from other SKS's wont work also.
All in all, I feel they were going for their own look, hoho must have liked to spice things up, there's just no other reason.