Yay! I found it! My friend Christine (I hope she's okay with me referencing her as my 'friend' :)) had this posted about a year ago and I saved on my other computer (long story, it doesn't work) so I can at least know where it is and savor its goofy cartoony goodness.
You're probably asking "But WHAT is it?"
It is the model sheets for the Beatles cartoon by Al Brodax...even though on the sheet itself it says "Blueprint". Whatever. Its a MODEL SHEET.
I'm wondering what they (the writers, animators, Al Brodax himself, etc.) watched to come to the conclusion that this is how the Beatles act, walk, and carry themselves. Did they just watch "A Hard Day's Night" and go "Welp, that's all we need to know about that! Start drawing!"?
I get the feeling this "blueprint" was lost repeatedly because the quality of the Beatle cartoons tends to fluctuate.
Notice how Paul is drawn in a different way than in the first video? See, its aggravating for me drawing the Beatles in this style copying from the cartoons because I watch one of the cartoons and realize that I've been them WRONG. I had to change and rework Paul alone about three or four times. These model sheets are the closest thing they had and they don't even had the center lines on the head or the standard 'pears and balls' body construction. (See here) If I was going to describe these Beatle 'toons in anyway, I would say they're made up of 'sticks and rectangles'.
Bodies-boxy shapes or rectangles
That is a big reason why I didn't copy the Beatle cartoons EXACTLY. I mean, early on, I tried but it got to be a pain in the ass when the finished product didn't look a thing like the thing I was copying. So I just took what I knew the cartoons where trying to convey about how they looked (John has a boxy jaw and an arrow-shaped nose, etc.) and adapted that using my own style, which I don't know how you would describe it.
That's why its been an uphill struggle with these 'studies'. My way of doing things is to copy things best I can and do things my way, which is apparently wrong. (at least when it comes to copying the Preston Blair studies.)