Dan is correct.
I recently rebuilt a Taurus PT1911 for a friend and it had that damn, infernal Ambi safety on it, which is a MIM part and completely worthless in my opinion.
I bought an all steel, single side safety and we did have to do a very minor bit of fitting to make the safety fit and work correctly. The bonus was that I was able to slightly stretch the spring that pushes the detent against the safety to add just a bit more tension so the safety had a more positive ON/OFF click to it.
You can do it yourself, just go slow and be careful. It's not rocket surgery, but it's important that you take it slow and make triple sure it engages solidly in place before going hot with it.