Hi guitarfreak5.
It is unusual to see a solidbody Teisco with the 3x3 tuners. The only solidbody guitars with this headstock configuration built by Teisco that I'm aware of were built in the 1950's.
The body on your dad's guitar looks essentially like an MJ series guitar from the early 1960's. Here is a picture so you can compare:
There is a gap in my Teisco knowledge between the guitars made in the mid 1950's and about 1963. It is possible that your dad's guitar fits into this time period since it appears to have the neck of a 1950s Teisco on an early 1960's style body. Does you dad know the year of the guitar in the picture?