You have a backup of the moodledata for the old site. And you have that downloaded ... correct?
Uncompress/zip whatever the moodledata.
A directory in there held all files uploaded ... filesdir.
IF ... IF ... you made course backups and didn't save those to a designated directory, you could have .mbz files by another name in the un-compressed moodledata/filedir/
Got a Mac or a Linux server where you have terminal?
You could extract only the filedir directory.
Then from terminal in that directory
[root@sos filedir]# file -b ./*/*/* |grep gzip
If there are backup files in there ... you will see a listing like:
gzip compressed data, from Unix
gzip compressed data, from Unix
gzip compressed data, from Unix
gzip compressed data, from Unix
gzip compressed data, from Unix
Dunno the file location nor it's name ... but those are .mbz files.
How large is your moodledata/filedir directory? If not too large I have an offer you can't refuse! (you could and do it yourself, I guess!) PM me here on moodle forums with info and we'll 'talk'!
Or ... you could restore the .sql file -> oldmoodle. Then query the mdl_files table for contenthash,filename where filename like '%.mbz'.
That would show the contenthash which is the path and filename of the .mbz file in moodledata/filedir/
Use that info to copy out the contenthash named .mbz file by the matching filename seen in the query to a directory where you can upload to new 3.9 when ya get it running.
Above might be less work than doing what you are doing!
'SoS', Ken
'SoS', Ken