Don't listen to Pro-NRA, he's probably crafting a PM as we speak, offering $300 and telling you what a big favor he is doing offering you that much!!
Yeah that is a shame some clown sanded it down, but the good thing is the stock looks absolutely cherry... and that's harder to find in my opinion. Have the bore checked and then decide if it is worth it to re-park or if the bore is worn, find a NOS barrel (they are available if you know where to look) and have an experienced smith install the barrel and park all the parts to match. You'll have a beauty of an 03-A3 that way.
If you send it to Dean at Dean's Gun Restorations, (dgrguns.com), he will make it look like new.