The major difference between the Yugo and others is the grenade launcher and related stuff. The bayonet connects differently than the others because of the launcher, and The bayonet is 14" long rather than 12" long. There is a gas cut-off switch for using it as a single shot gun when using the launcher. I have one Russian and one Yugo and look forward to shooting them soon. Check the door on the buttstock and see if you got a cleaning kit with it. Sarco sells parts and accessories for the SKS, but be patient when ordering. I ordered some stuff from them on the 6th of this month and have not gotten anything yet. The price you paid is pretty low. J&G was selling them for $325 a couple years ago.
Unlike the others, the yugo"s barrel isnt chromed lined. If I remember correctly, they didnt have the know how at the time of manufacture. Does it matter? Not really just remembergive her a good clean/lube afterwards. I have one and considering all the rounds I put through it the bore looks just as good as it did the day I got it.