[Bulldozer]

I've inherited this nifty little, but heavy, Colt double-action revolver. I've no idea as to its vintage or even model. I was hoping that some of the good folks here could ID it for me.

Here's what I do have on it... black plastic grips with Colt logo. Heavy steel frame with ejector rod exposed. Fixed sights, but a heavy barrel. # on bottom of grip frame is 212524. Barrel; says COLT DA 38. Etched inside the frame where the crane seats is H-590, as well as on the thumb release for the cylinder. It holds six cartridges and has a 3 inch barrel.

I've attached three decent pictures. Any help would be most appreciated.