Like you Scott, when I see a K prefix I think Kay.
There is a Kay model K-100, but it was offered much more recently than the date buddy suggests for his guitar. Here is a picture from a 1979-80 Kay catalog.
Kay flattop acoustics from the 1940's through the mid 1950's had 2 digit model designations. In the late 50's through the 1960's the company switched to 4 digit model designations on their acoustics.
These observations lead me to 1 of 2 conclusions.
1. buddy's guitar was produced more recently than he thinks
2. buddy's guitar is not a Kay.
I think you are right, it will take a picture to begin to sort this out.
