I was at an auction in Cody, WY (my home town) where I acquired your Dad's Colt about five years ago. I started researching him and have had mixed success in getting information about your Dad.
This pistol was from the 101 Ranch. They gave these pistols to everyone who worked there.
I finally got around to taking some pictures of your Dad's Colt 45. As you can see, the pistol has beautiful engravings and carved wood grips. Under the barrel is the name, "J.Case" but I could not get it to show up on a close-up photo.