Identify a Smith revolver

[mobiker]

I have a Smith & Wesson revolver it looks like a model 15 I have with a thinner barrel and dull blueing. It is made in the USA Sprinfield Mass on side just like the model 15. On the other side it has: POLICIA NACIONAL DE COLOMBIA If you open the cylinder it is not identified what model like the model 15 is. The serial number is D23***. It is a 4" barrel 6 shot 38 spl non adjustible sights. Any help would be appreciated. Also what years where the Model 15-3 produced that is what my model 15 is.
Thanks Charlie

 

[Jim Watson]

You have a Military & Police made before 1957. Designated Model 10 when they assigned numbers instead of names.

A Model 15 has adjustable sights.