Forget the scope rail, this thing will never be accurate enough to use it to its' full potential. Instead, you should try to make a Mauser-style upper handguard out of matching color wood. The fully exposed barrel and upper receiver makes it look like you've lost some parts on your way to the range, lol!
Also, the mag plate should be made flush with the bottom of the stock to improve looks and ergonomics further (again, like a Mauser), since it can only legally hold 5 rounds anyway and the rifle has been Bubba'd beyond the point of no return. Someone once told me that there exists a factory (commercial) 5-round box mag for an SKS. Maybe get one of those, if you can source one... or chop/mig-weld the stock one.
Interesting project to look at overall, but I'd feel so bad doing this to a military issue SKS myself, regardless of its' condition. There was a time where a lot of guys thought chopping inexpensive and plentiful Enfields into "sporters" was a great and neat idea too... and we all know how that panned out in the end. Just saying.