Ptlm: Well...how old is the Colt? Did the finish last until just recently? So you MAY have gotten a lot of mileage out of it? Try calling Colt's customer service. A shooting buddy of mine bought a Python at a pawnshop that needed re-blueing, Colt did it for $150 plus they check the gun for any potential problems (BTW, if they find a problem, you WILL have to pay them to fix it or they won't return your gun). They didn't find any problems with his Python. A factory finish for a good price likely couldn't be beat, and MAN do those Gold Cups look great in nickel!! (a relative of mine that's a cop has one)
However, I looked at that Checkmate Custom site, and their prices look pretty reasonable. Give Colt a call though-they seem pretty decent to deal with (I had to call them once to get an owners manual for my AR)
Edited to add: I have a Browning HiPower in hard chrome and it's pretty nice and eye catching-but not as much as the nickel. My HP is a 1981 model, bought it from a pawnshop and whoever had it before me DIDN'T take care of it, and it doesn't have a spec of rust on it. Checkmate offers hard chrome.