You're welcome. 
Grade 1 1/2 isn't used much anymore, but I would think that those who were brought up in the 50s and 60s still use it unless they learned Grade II Braille instead.
Blind children are usually taught Grade I Braille and then Grade II.
Blind adults are always taught the alphabet first and then proceed to Grade II. The only exception would be if a person has no interest in reading in which case they would only learn the alphabet for labeling purposes.
Almost all children's books are written in Grade II Braille. They have an awesome type of book called "Twin Vision Books" which have print on one page and a clear overlay of Braille with tactile graphics on the other. This is a wonderful way for sighted parents to read to their blind children or for blind parents to read to their sighted children. I wish I would have had something like that when I was growing up! 
