Avid Media Composer to FCPX?

I have a short film that has been assembled/synchronised into 60 timelines with English captions, on Avid Media Composer. The original footage is ProresXQ, which is perfect for FCPX but the Avid editor transcoded everything to MXF in Avid for offline editing.

My question is, how do I get his timelines which have english captions, into FCPX?

and is there any way to switch to the original Prores footage?

N.B. The attachements show the prores and mxf files respectively and they don't seem to match...

Has been many years since I used Avid and I never translated an Avid project to FCP.
But where I would start to search is how to export the project data only? I think Avid doesn't support XML, and if it would probably only FCP7 XML which you then need to translate into FCPx XML. As there is no direct export/import of editing data between Avid and Fcp you might need to explore going from AVID to Resolve to FCP. BUT getting titles converted between editing software is extremely difficult if not impossible. They most likely will look different or don't come across.
The actual media files are the least of your problem. What you describe as not matching media is caused by AVID always splitting media into video and audio as separate files (V01 stand for video only media, A01 for audio). Once you get the actually editing meta data converted you would relink to the original ProResHQ movie files.
To be honest you are probably better off to finish the project in Avid or start from scratch in Final Cut Pro.

In the beginning AVID was essentially an EDL generator for offline editing, the codecs were ... anyway . Six years ago AVID could not even read its own XML so the right way to go is still via EDL, a workflow test should be done too inspect the link in the EDL to the original footage.
EDL X can do a good job to bring the projects to FCPX but the app is a little expensive for a one shot.
apps.apple.com/us/app/edl-x/id539666579?mt=12
concerning the subtitles the editor can export an SRT for each timeline ...
I did not use AVID for nearly 20 years so
My two cents