Just my opinion if it were in my hands.....
It's already been refinished at least once but, at least they didn't buff the markings off. Refinishing it will far supersede what just buying another one in the condition you likely want would run you cost wise. The rust looks deep enough that after the grinding, it'll likely need to be welded back in for the holes. Maybe the rust looks worse in the pictures than it really is? FJA stamped typical mix master that isn't anything rare.
If you're looking for a decent example, even with typical wear like the CMP guns out there, keep looking. Value wise? couple hundred in parts maybe...
How is the condition of the magazine? What magazine?
The rust looks like the gun was sadly stored in the leather holster, so the mag may still be just fine.
Now what it might be a good candidate for - strip it, remove/grind out the rust and if it's not too deep to affect the safety condition of the gun overall, refinish in a cheaper cerakote and just have a good old blaster. Heck, it'll probably shoot just fine now after dropping in a new recoil spring.