Coming from the Avid world for 12 years and fairly new to FCP, maybe I’ve overlooked the obvious in your question and previous statements. But you can come back to a project with offline XDCAM EX footage and re-import the media through FCP’s Log and Transfer.
With the Log and Transfer window open, simply select the desired offline clip to the lower left window of the Log and Transfer window pane called the “Transfer Que.” A dialog box will then appear asking which media you want to have re-imported (Selected or All offline within selection). Make your selection and select OK.
Was your question more complicated than what assessed?
Paul Grady
Dewitt Smith Video
Atlanta, GA