OK, what you have is a standard issue Chinese made SKS (Simonov Karabiner Semi-avtomatika). Don't know what you paid for it but it was a good buy when you did - where else can you find such a rugged semi-auto in 7.62x39, eh??
Let's see:::: clean the cosmoline out of it and take it to the range. That looks like a earlier SKS, so you may have a full length chrome lined barrel - if it is a later version your rifling may stop a few inches short of the muzzle.
I don't know that anyone has really ever used the bayonet as a shooting monopod though but these rifles should give you 2-3" at 100m from a bench.
Very easy to field strip and clean, probably the easiest is to get a 5 gallon can/bucket of kerosene and just dunk and swish the dirty stuff, dry and then reassemble.
If you have a long reach you amy want to install a 1" buttpad.
Don't know when it was made but as long as the numbers match and the headspace is good there should not be any issues.
Raise the front sight post to get the poi to poa at 100m and you should be good to go. Let us know how it shot.....
