Anything and Everything is fixable... it just depends on the amount of time, effort and money you want to throw at it..
I'd first look at the grates closely, use a straight-edge of some sort, like a ruler or short board,, check to see if the grates are warped, that is sagging down in the middle.. this can keep them from rotating and meshing with each other correctly.
Then check to see if there is a baffle plate above the fire, sort of a shelf that makes the heat/fire come forward then back over the baffle to get to the exhaust exit.. If the baffle is cracked, or badly distorted, then maybe the stove was overheated.. BUT this doesn't mean it can't be used safely..
I'd get a can or two of PBS Blaster at your local automotive supply store [NAPA, AutoZone, etc] or some other good rust pennetrant. soak the pivot points, hinges and linkage for the shaker and the hinges and latch on the doors.. Don't forget the draft [air] control knobs or sliding doors.
just wiggle the parts, handles, doors every day, then apply more pennetrant,, in a few days it will loosen up.
Unless the stove, the door and grates look like they are so distorted that you think you are seeing them in a fun-house mirror, I'm pretty sure you can make this stove work for you,, you certainly can't critizize the price.
I'd plan on new gaskets all around, and I'd wait on deciding about glass or steel panels untill you discover how good the stove's condition is,, if it is stright and not warped,, I'd spend the $$ and bring it back to 'new' condition, and enjoy it!!
Please post some photos of the stove and the interior of the firebox. A photo of the bottom of the shaker linkage will help too.. There are plenty of guys here who can help [make suggestions] about getting your stove making heat.