raw52, Something you may not know about 1911s. Nearly all of them come with either MIM or cast parts. These include the hammer, grip safety, thumb safety, slide lock, disconnector, and sear. Between cast and MIM, the MIM parts are much better. They tend to be tighter tolerance and look no different than a forged part (unlike S&W MIM parts). Cast parts are more crude and don't finish as well. This goes for blue and stainless parts alike.
I doubt you can find parts made from bar stock. Not only are they hard to find, they are very expensive and are no better than MIM.