It's a good looking carbine. Down here in the states, dropping $800 for that would be a no-brainer, but I honestly don't have a clue how much as-issued SKS-45s are going for up north. If it's only a hundred or so over what is typical, I'd say you're probably ok. There's nothing in the photos that screams warning signs to me. Maybe, just maybe, the stock's been refinished, but otherwise it certainly looks as-issued to me.
When you say "It’s got the same markings as an SOK-sks." what does that mean? Exporter/Importer markings? I'm unfamiliar with the term SOK-sks.