BudsGunShop.com - Restoration

Brett, it will be a moderate effort depending on the condition of the model you get or I would just take it to a local gunsmith for cleaning if necessary. Cleaning services are usually pretty reasonable. Cheers and stay safe!

What I did with mine was a light sanding with a soft grit sandpaper just enough to take the original finish off and use birch wood Casey’s finisher and rebluer and it looks amazing

There really shouldn't be any rust, and it'll be very minimal if there is. These things are drenched in Cosmoline, which protects them from the effects of oxidation, and rust. The Cosmoline can be a chore to get off, but some boiling water, some denatured mineral spirits, and some elbow grease and she'll look good as new.
Or if you know someone with an ultrasonic cleaner, then you can do it the easy way. Some gun smiths have these and rates are fairly reasonable. To have it run through the ultra sonic.

Brett, shouldn't too difficult with a little time, elbow grease and the correct materials. Good article here >>> gunpartscorp.com/blog/how-to-remove-rust-from-a-gun .....Also, here a thread for stabilizing rust on SKS >>> theakforum.net/threads/how-to-stabilize-rust-on-sks.321698/