System 11's generally don't take kindly to having the mylar lifted. It might be different for this PF which was never installed. Unfortunately, you can also see planking in the playfield paint in several of the grey areas which speaks to how this PF might have been stored. Which may also mean you'll have a color mismatch of the grey after lifting the mylar. There are a few other scratches you can see in other spots on the PF besides the inserts (ie look behind the guy in the red hat with the two kids facing the barker next to the Boomerang hole.) Even CPR had issues with the inserts crackling on their repros.
If you can get it for the right price it's worth it. However, if it was close to the price of a CPR repro before doing any work to it, I'd have to think long and hard about spending the money.