I understand this is advice, and there is more than one way to skin a cat. I'm not saying it is bad or wrong, but I do disagree:
Do not change the order of your original appraisal. The client has a copy of the original and will likely ask you to change the order back.
I find the fact that the client has a copy of the original report irrelevant.
The final report is the final report. In theory, no comment is necessary; only a new report date. In practice, I think it is prudent to explain in the latest version why things have changed from an earlier submission.
The new report is just that: a new report. Take out, add-in, or do a combination of the two with the sales one thinks best reflects the subject and are most meaningful to the analysis.
Be careful with your commentary, again, what makes these sales "superior"? If you use that word you sound like an idiot for not having found them yourself .
I strongly disagree. I've talked to many appraisers who won't change their reports even when presented with superior data simply because they do not want to look "like an idiot".
By implication and anyone would infer, if there are new sale comparables added and adding them changes the opinion of value, they must be superior in some respect to what was originally analyzed (otherwise, they wouldn't move the needle). Indeed, the only reason the value does change is because they are superior to what was originally considered.
OP: If you are hung up on using the word "superior data", then don't use it. I wouldn't flinch at citing it as being superior to the original data analyzed; that is the entire reason why I've reconsidered the value.
Again, good luck!