Are your CDs in folders? If yes, then MP3TAG can autonumber the disc numbers and track numbers for all 1300 tracks with just a few clicks. No need to manually cluster 85 CDs and number each one separately. One button, every track and disc numbered.
You’ll also need to work out how the 15 parts are being named. Is this as “track 1, track 2”? Or will it be “Paschale Mysterium, part 1” etc?
I am not dissing Picard here as it is great, but bulk naming an 85 disc set from a zero start is a trick that MP3TAG can pull off with less clicks. The ability to bulk copy between text files and tags can be a huge time saver.
What are the files currently called? I am used to doing this stuff in MP3TAG and can help guide.
Once the basic tags are in place, then we can feed Picard clusters to upload to the database. That is when Picards skills really kick in - database integration.