Restore music metadata after SSD loss

So a month ago I lost my 2020 MacBook Air's SSD (which had been running Catalina) to a coffee spill; the computer is now fixed (and upgraded to Monterey) but the drive is wiped. The documents had been backed up to Dropbox, but the music folder was not. I have my previous MacBook (running High Sierra) that contained my music current to mid-2020, whose stuff I have copied over with Migration Assistant, so I do have that at a minimum - but I'd like to get things back the way they were before the spill last month. I'm not worried about having to re-download the music itself. What I'm worried about is my precious metadata, which are the reason I still use Apple's music app instead of Spotify. Since the mid-'00s I have maintained a carefully curated random-play playlist: it uses nested smart playlists to pick songs based on their star ratings and how recently they were last played. This is by far my preferred way to listen to music and I want to keep it. My hope is to keep all the star ratings and last-played from pre-spill times (Nov 2021) so I can get my music back to the way it was. I have three places that this data can be drawn from: * Before the SSD died I was able to copy the "Music Library.musiclibrary" file from the old computer. I was NOT able to copy all the music, but I did get that file. * My iPhone has most, possibly all, of my music on it from before the spill. * And everything up to mid-2020 is still there copied over from the older computer's iTunes. The simple thing would be just to import the 2020-era iTunes library to the Music app on the new computer, but if I left it at that I'd lose over a year's worth of star ratings and last-played data (plus the playlists I created during that year). Since I have the old Music Library file and the iPhone, I'm hopeful that I can get the ratings and last-played back using those. I'm just not sure exactly how to go about it. Given the parameters of the situation above, can you please advise on the most effective way for me to get my music setup back to pre-spill status, including playlists and metadata? Note: I don't have an Apple Music subscription. My iPhone used to sync with the old computer, the one that died.