Glad to hear that you got your music back.
For the missing music:
You may be able to find those missing tracks in those folders you found. Since you have your iTunes Library with the majority of your music, you could use the same search term (*.m4a OR *.mp3 OR *.m4p) in File Explorer in each of those folders and drag the music and drop into iTunes (just like the iPod) and the non-duplicate music will be added to your library.
As for the hardware:
You may want to consider trying to get a new to you iPod Classic from one of the used item sites. Be prepared to get broken ones. You may be able to get a replacement port from one, or migrate to a one that is in better condition.
There are some repair sites on line (be careful) that may be able to replace your port as well.
For the missing music:
You may be able to find those missing tracks in those folders you found. Since you have your iTunes Library with the majority of your music, you could use the same search term (*.m4a OR *.mp3 OR *.m4p) in File Explorer in each of those folders and drag the music and drop into iTunes (just like the iPod) and the non-duplicate music will be added to your library.
As for the hardware:
You may want to consider trying to get a new to you iPod Classic from one of the used item sites. Be prepared to get broken ones. You may be able to get a replacement port from one, or migrate to a one that is in better condition.
There are some repair sites on line (be careful) that may be able to replace your port as well.