If it's actually a Colt, perhaps it would be worthwhile to investigate replacing the 7 1/2" barrel with a new 5 1/2" barrel.
A gunsmith could unscrew the old barrel and install the new one with minimal blemishing, using the tried and true rosin-coated and carefully shaped wooden block method.
The gun is stripped down to barrel and cylinder frame only, the barrel is clamped in the blocks in a large vise, and a hardwood lever is inserted through the frame. A sharp rap or two loosens the barrel and the frame unscrews.
The new barrel goes on in reverse. Then the cylinder gap is adjusted by filing, and then smoothing the forcing cone.
Apart from the barrel cost, the gunsmithing charges might actually be less than having the old barrel cut down and a new front sight made and installed.
As well, the barrel surgery may or may not turn out to be what you hoped for.
However, the barrel replacement would retain the original factory appearance of the gun.
Finally, the removed 7 1/2" barrel would be undamaged and could be resold to defray costs.
It could be installed on another revolver, with some expert fitting by another smith.