The grips are also not correct.
During Colt's 150th anniversary year they used the so called "Large Pony" medallions with a "150" on the medallion.
For several years after that they used the Large Pony medallions only they didn't have the "150".
The grips on your gun were made sometime during the post-anniversary period and may have been bought from Colt as an after market item.
"Usually" smooth Python grips are grips someone sanded the checkering off of, but these grips are a little more fancy grained then Colt grips of that era usually were. Colt did sell fancy grained smooth Python grips, and these may be a pair.
As for the incorrect features, finding Python hammers, triggers and sights is near impossible, and finding them in nickel is like finding a gold mine in your yard.
In no case would you be able to recoup the cost of buying new parts even if you could find them and having them installed.
In any event, installing new parts to make the gun look original is somewhat unethical. It's no longer in original condition.
If you plan on selling the gun, sell it as-is.