I was talking to someone on Facebook about 1522, and he was saying that part of the reason why 1522 was retired was because it needed bearing work. I was wondering if this was true or not.

Here's a quote from a few years ago from Don Wirth AKA "Frisco1522" over on Trainorders.com regarding the retirement of 1522:

"1522 was retired and the SLSTA was dissolved in 2002. She was due for her 15 year FRA work, significant boiler work needed and doing that would have had to been contracted out, insurance costs has skyrocketed since 9/11, the cost of leasing cars for trips that weren't selling out became excessive and the railroads were hunkering down and concentrating on freight traffic and also were getting short on manpower. The enthusiasm from them for steam trips was waning. All of these issues added up and the organization's board decided it was time and we went out on top."

1522 had new crown brass installed on the last rebuild and they are fine. She has roller bearings on everything but the driving boxes plus a sophisticated temperature monitoring system.
She does need a lot of roof sheet work, which can get very expensive very fast if you have to contract it out.
If I were rebuilding her today, I would alter the crown brass and convert her to oil lubrication on the drivers. The crown brass would have to be altered to work best with oil and new cellars would have to be built and other lubrication methods utilized on the driving boxes.
The fact that the hard grease that fits the old Texaco formula is not around any more to my knowledge plus the success with the SR 630 and others using the PB&J oil would be enough to convince me.
She does need the suspension leveled, but that's not a huge deal. She also needs to be "squared up" again. She is slightly out of square and it's annoying as hell and to have a place where adjustments could be made and tried at the same time would solve that problem. When your only chance to really try a change is on a trip, it makes it very hard to fine tune.
I truly miss the old girl and I lived a dream for years after promotion, but reality has to sink in. The market was flat, insurance was sky high, it was going to get harder to get out on the main line and not owning your own cars was too expensive to continue.
Couple all of that with the 1472 and accompanying boiler work, plus whatever is always hidden until you get in the middle of the work makes reality a bitch.

The great thing about this particular locomotive is that, its condition was known when it was parked. If the tables were to turn in say another 10 or 20 years, it wouldn't exactly be starting from scratch, similar to what's going on with the 611 now. My questions is, was this stuff documented for future use if needed? As unlikely as it may seem, you never know when the tables can be turned. After all, who would have ever thought we'd see the 611 run in our lifetimes?

For this engine to operate again for a private group, wouldn't its owner (the museum, and by extension, the county, I presume) have to agree to lease it? And to allow an outside group to operate on museum grounds? Is that likely to happen again?

Chris.

Yes Chris.
For 1522 to rise from the ashes someone would have to approach the museum with a sound business plan, cubic dollars and a highly qualified restoration crew all lined up before they do anything. The last thing the MOT would need is an engine torn asunder and scattered all over the place by a crew that doesn't have a clue what they're doing. They don't have the resources to deal with that.
Never rule anything out, but they will not waste time on a plan with no preparation. I wouldn't either.
The very first restoration was a very carefully planned operation. Nothing less will work now.