What is this old Colt?

It looks like a commercial Navy model.
The Navy Model didn't have locking notches on the outside of the cylinder.
If it's a US issue gun there'd be US stamps on the butt with the serial number, and a government inspectors stamp on the frame just above the cylinder release, usually R.A.C. for government inspector Renaldo A. Carr.

This looks like a commercial model with the original 3 1/2" barrel and hard rubber grips.

Thanks, DFW--what do you think it's worth--ballpark anyway? The grips are good but one corner has a small piece missing. I think the photo missed it. I'm guessing maybe $250 but I don't know how rare those 3" barrels are.

I saw that one myself and passed on it. I think the barrel was cut down.

DuWat--are you in the burg?

I have one like it, but with a proper 4.5" barrel... Definitely a 1889 Navy, like stated, civilian model. From the look of that second screw hole for the locking lever, it might be a late model. On the inside of the frame, is there a hole for a cylinder bolt - but no bolt? I have one of the last ones made, it's on a 1892 frame (hole for cylinder bolt with no bolt installed) but has a 1889 cylinder without the locking knotches. I bought mine for $150 bucks, but the lockup and timing needed work. Colt made around 31,000 of these, so if the serial is over 31000, it may be a sad 1892 that someone's thrown a 1889 cylinder on....

As I recall I think it was a 41.