In the meantime, I found an online program that can separate the guitar from the voice, and this seems to have done a satisfactory job to separate them.
I’m a complete amateur with Audacity, but I played around with noise reduction and filter curves at random for the now isolated vocals track; without really knowing what I was doing.
I watch a few videos, but these were mainly about narration and how to improve podcaster voices, the instructions there didn’t take away the harsh tone of the vocals
The vocals are still harsh across most of the song, is there any filter to reduce the harshness, even carpet bombing to obtain any slight improvement?
I understand your comments on new AI cleaners.
Just any improvements at all would be better than the current quality like a one size fits all quick fix?
A quick & dirty method would be to increase the contrast of the spectrogram,
which reduces the velcro-like noises, then drown it in reverb, (which can hide a multitude of sins) …
Increasing the contrast adds digital artefacts, (but so will using spleeter or similar separation software).
The contrast-enhancing plugin I used was an old one called DtBlkFx
The reverb I used was Valhalla supermassive, but any reverb would do.
To do justice to your 70’s recording would be like restoring a painting: it would take weeks to do it properly.