I think you did great with what we had to work with. You can obviously mix very well.
The song is fun, all the musicians are giving a great performance, no doubt, but man is this one hot mess to mix or what!

I won't be saying what I didn't like because knowing the stems, these are the same things I didn't like in my mix and are inherent to the tracks.

From an artistic point of view, there was one thing that I would do different (and did in my mix): I feel that there is a very strong dialogue between the mandoline and the electric guitar, and I found that in your mix they were more or less in the same area and space. Also, many times the electric guitar was completely burried that I couldn't hear it.
These all might be artistic choices that are completely valid. I thought to point it out just in case they weren't.

Really great job!

Hey Adrián, good one! For me the reverb on the lead vox is too present, I'd turn up a tad the horn section and turn down the toms and clean a little bit more the lows.. what did you use on the horns? A pitch shifter? ;P

Hi Adrian . Yep .. the reverb is the main issue on the vocal...pull it back and maybe shorten it little. a little less low end on the bass
Sound like you have the 'vinyl' plugin in the Brass!?
Over all the balance is great...

Hey Adrian, mix sounding pretty tight! Personal preference but I think the electric guitar needs to go up. It plays an important part in establishing the groove for the song and helps drive the song forward, so having it turned down and hiding in the back keeps the song from really propelling forward.