I have the same rifle (981T). I bought it to have something that would feed Collibri (no powder) .22s. They are shorter than .22 LR and will not feed in magazine fed rifles or handguns. (Yeah, I know: they are made for revolvers.)
From the photos I cannot see all the problems the guy describes. And while the gouge on the crown looks bad---I doubt it affected performance.
Still, the guy is really good for a non-professional gunsmith. And, yes, brave to dig into it. But as he said, it's only a $180 rimfire...