Glenn.
This is another example of the drawbacks of linkage!
The first profile is correct and should not be changed.
The FAA registration cannot be changed by linkage, only by making changes using the Correct or submit additional aircraft data in the profile. These corrections would appear in the profile but the original FAA data is retained in the database so that duplication doesn't occur at the next FAA download.
The two profiles can then be linked by a comment in the profile.
It seems to me to be the only way and is now fixed.
Malcolm.