Welcome to the forum and you have a great 1st post!
That is an interesting gun with an extra story behind it.
The engraving looks like classic Helfricht factory engraving style but it has a blackpowder style frame (pre 1896) but the front sight is the large profile which dates to 1911 or after and it has the deep set medallions in the stock and that's a 1911 or later attribute also.
The gun very well could have been returned to colt for rework sometime between 1911 and the early 1920's.
Valuation is going to have a lot to do with what is original and who did the work and is there any real provenance tying the gun to a Texas Ranger. But I'm seeing several thousands in just the pearl carved grips.
Will be a major coup if that piece can be tied to Gus T. Jones. Agent Jones was involved in the Kansas City Massacre and Urschel kidnapping cases of the early 1930's and was one of the Texas Rangers J. Edgar Hoover called on in the early days of the Bureau of Investigation to deal with criminals of that era. Agent Jones and Agent Charles Winstead (present at the killing of John Dillinger) were instrumental in training the early agents during that time because they both were experienced gunhands. I hope it was his Colt.
Through over 30 years of collecting single actions I've seen several single actions owned by the rangers that may have started out life as a plain working gun and they sent them back to colt to be "dolled" up or by some unknown engraver. This one looks classic Helfricht factory engraved to me.
This makes the 3rd one that fits in that 1917 to 1920 time period of use.
Is there any family connection to Ranger Jones or any story handed down about him that ties him to the gun?
See the numbers that I have circled in red down inside the loading gate? Not the numbers on the outside edge, but the ones down inside......
Those are factory bin (rework numbers). Gives evidence to the fact of going back to colt for rework. If you took the gun apart I believe you would see those same numbers stamped on every part (on barrel under housing, housing, front of cylinder, under grips on straps, bottom of frame, (perhaps the side of the hammer where you can't see it in the gun).
I'm sorry but have no real story to tell. I bought it from a gentleman that obviously did little to no research on the gun. It was his fathers that passed away a while back and he needed money so he sold it to me. I had no idea who Gus Jones was until I got home and did some research. On one side of the grips it has an eagle that is embossed holding a gold crest that says Texas Ranger and on the other side of the grip it has his initials in gold GTJ in cursive. They appear to be real gold. on the back of the handle it has his name Gus T Jones engraved in.