Smaller diameter wheel in front. When?

Your great advice in your answers to my question about the front axle on my Model A convinced me to keep its current '48 axle, toss the discs and install F1 brakes, and lower the front end with tire selection. Which prompts my next question.

When did it become common to put smaller diameter wheels on the front? '50s, 60s, later?

 

I think it was the early sixties - the Bob McCoy 40 Ford sedan comes to mind.

 

I was thinking early '60s also. Maybe prior to that someone did it with 16/15 combos but I know it became popular to do 15/14 combos at least north of Monterrey in the very late '50s to early '60s.

 

I have 14" on the front and 15" on the back of my coupe. I think today you have more options with tire sizes. My '41 truck gets a rake just by 60 series on the front and 75s' on the back.