At the beginning of the sixties, it was assumed that stereo would never prevail. Therefore, a lot of time and effort was spent on the mono mix. The stereo mix was created as a necessary evil in all fast. Since today everything is heard in stereo and we really only know the stereo mixes, which stand out because of their blatant panning.
In contrast to modern productions, the tracks could only be panned hard left, hard right or center. For example, in the old recordings the drums and the bass are often panned hard left, the guitar is panned hard right and the vocals are in the middle. With the old Beatles recordings even the whole instruments are panned left and only the vocals are panned right. This kind of panning has an immemorial influence on the sound.
For the effects I have also oriented myself to the devices that were available to the recording studios at that time.
In the Abbey Road Studios you can use the REDD consoles. REDD stands for the in-house Record Engineering Development Department. These consoles deliver the classic British sound of the 1960s. A plugin that strongly follows the sound of the former REDD consoles is the Code Red Free Plugin by Shattered Glass Audio. It captures the bold and punchy character, and the warmth of the old all-tube console.
The Antress Modern Fire Chainer is a nice clone of the Fairchild 660 Compressor.
The Fairchild Compressor is the studio compressor par excellence. It has a very special warm and silky sound that has always been used to enhance vocal tracks. I used the Fire Chainer for my vocal tracks.
Finally, I use a plugin that simulates a tape machine. This gives the song a warmer sound and sticks the individual instruments together more.