Double LP Side Numbering Scheme

That goes back to days of the stacked record playing. When console stereos had turntables they had a long spindle with a arm to balance the records that were stacked above the platter. The tone arm would be prompted thru a mechanical connection that would allow a little trigger holding the records stacked above the spinning platter. The trigger would release one LP and it dropped to the spinning platter and the tone are would move over and lower onto the lead in groove. At the end of the side the tonearm moved back to the rest and another LP dropped onto the spinning 1st LP. 

So the numbering was a convenient way to play the records in order of sides 1&2 then you'd flip over both LP's and play sides 3&4. 
 
Just as additional reminiscing, that is why the outer edge and label are molded higher than the playing area, to keep them scratching each other while dropping and gathering traction to get up to speed.
So it's pretty obvious VTA, accurate speed, rumble, etc. weren't a major concern. Sadly I confess this was what we had when I was a child. I had no knowledge of the need for the precision required to extract music from vinyl in its best form. 

Sorry to be over winded on the subject, I just got locked up in the memories.  Crap! I getting old😳

Theo,

Thanks for the reply. Makes perfect sense to me. But I still don't like it! :~)

I’m getting old too. I remember as a tiny kid my grandparents had a 7 inch, 45 rpm RCA changer that played a stack of 5, 6 or more discs from classical box sets in such a numbered and ordered fashion such that the stack would play sides 1,2,3 and so on and then you’d flip the whole shebang over for the 2nd half (sides 7,8,9, etc for a six disc set). Ravel’s "Mother Goose Suite" was one that was played to me often, so when I heard Joe Walsh’s synthesizer version of the Pavane from the Suite on his "So What" album as a teenager, I knew instantly what that music was. Imagine, 3 or 4 minutes of music, then a short fade, record drop, and fade up. By comparison, 8 track was far less clunky, but this was how extended pieces were played back via stamped disc prior to the LP. The plastic was somewhat brittle too, but not as much as the former 10 inch 78 rpm shellacs, still, you could break them easily.

https://www.youtube.com/watch?v=cO0PuTWjuF8

Just put on my double LP of Focus - Focus 3 and its numbered 1,2 then 3,4. I guess the record company thought buyers of Focus 3 wouldn't use a stacker. Or maybe it just isn't necessary to play this studio record in it's original order? Or maybe I'm just over-thinking this.........

In the 70s there was a move toward single sided play when one got to high school and college, and we started taking care of our hard-earned records, at least that's how I recall we no longer wanted cheap record changers for fear they would damage the surfaces.

Sounds about right. Coincided with the time I switched from buying singles to buying LPs. With LPs, I didn't need, or want, a changer. With singles it was a necessity......

I have a triple LP numbered like that . It sure is a PITA!