Great track again BTW
To try to answer your specific question : the Linndrum type of sounds & most of the synths sounds and especially the one playing at 2:35 are definitely sounding 80's to me. I'm perhaps less sure about the white noise used in transitions & the violin used during the break as well as some choirs/vocals.
You could perhaps expect some Juno or Solina type of violins in a typical 80's track, many sounds where also coming from the popular Yamaha DX7 or the different models of the E-mu Emulator at the time. This violin sounds more orchestral than this to me, though the E-mu Emulator was quite good as this as well.
Also the way this violin is played here ( a little bit staccato or with a notion of rhythm anyway, not good at music theory terms, LOL ) is different from a 80's classic track for me, many tracks were based on long, sustained notes & chords for synths & even some kind of guitar sounds.
I think that's always the issue when trying to make a track in this genre, if you don't want to take a risk to fall in "pseudo 80's synthwave" or "Pop-wave", then the best way is to just use sounds very close to the originals, enhancing the track with sounds that our ears & brains can't refer to as "authentic" ( for those old enough at least, LOL ) will jump out right off the track and people go : "ah wait, it's a modern recreation, not a classic 80 track" I think.
The rest is about tempo & arrangement, you can have the right sounds but use a different progression or tempo and the track will possibly fall in the "Pop-wave" or "Retro-wave" register. That's the all difficulty when creating tracks from scratch in this genre IMO.
For classic sounds references, this guy is amazing in his live performances & he's just using hardware.
On live shows he mainly playback good-old golden classics but he has released album and original music synthwave music too ( search for his "Perplexagon" series ) You can check his YT channel here : https://www.youtube.com/channel/UCV-5d2ZbKBRCGaG3MXXfXcw
And an interesting Ted's talk here too : https://youtu.be/bcxpGPnloS8