Welcome to the forum. You'll find the Highway Patrolman, or Model 28, has a large following here. My first handgun was a Model 28, and I wish I still had it.
You can search to find a lot of information about your Dad's gun. Here is an informative thread - there are lots of others.
http://smith-wessonforum.com/s-w-rev...wn-pg-4-a.html