I also have a couple of old revolvers that have been handed down. There is not much value monetary to them, but there is intrinsic value. To me, these pieces tie me to my past family. I may not have known them personally, but they are my blood.
I plan to pass these on to my boys. I have tried to make the possession of these important to them. I want my boys to keep these for their sons if there are any in the future.
That makes these guns heirlooms to us, as yours should be to you. Find out some personal information about the original owner. This becomes the prominence for the item. That adds value to it.
Here is an example. When my oldest son graduated from High School, I bought him a Henry replica rifle. This is a rifle that he really wanted. I bought it used, no box or papers. The guy claimed it was never fired... yada yada ... It was in good shape and the price was OK.
I then wrote the company that imported it, and explained why I had bought the rifle. I asked if there was any info or maybe a box that I could buy. They told me that they did not have anything. But I received a letter from the president of the company on letter head personalized to my son. A signed copy of the first years catalog. He also included a photocopy of a magazine cover that showed the rifle and a pistol they made.
This adds a whole lot of value and prominence to my son's rifle. This makes it a family heirloom to him. He will probably never consider selling it.
Yes, your colt is a family heirloom. Be sure to post a picture of it.
I know this is a long reply, but I hope it answers your question.