I always wanted to point this out on the later Sears Harmony or Silvertone Guitars. You'll see lots of people refer to these as "spacedot" or "atom" or even "atomic" because of the headstock logo. What I want to show you is it's actually just the letter S for Sears
and the letter R for Roebuck.
So you see, the spacedot or atomic is just a fancy graphic for Sears and Roebuck. This symbol was used on many of the acoustic and electric guitars sold at Sears starting around the early 1970's.