After you file

Thank you, @fanfare !  I will plan on moving forward with a normal amend, with the only changes being as mentioned.

 

I'll make a note to come back and update this thread if the IRS tells me I've done something wrong in this process or does not refund me my overpaid taxes, so others who might end up in this situation can see what happened.  If I post nothing, assume it all worked out!