It looks to me like the tools don't fit properly and are only engaging at the very end. If that's how mashed they are, my concern would be how much damage they have caused to the nut?

With the greatest of respect, if he's a Sheridan expert he should sort this out without needing input from the customer. I'm sure he's a nice guy, but If the gun was mine (and had great sentimental value), I think would find someone (like Ped) who really knows what he's talking about.