Have you considered replacing the crappy plastic mainspring housing Kimber puts on their pistols with an aluminum one from like Ed Brown of similar pattern to the rest of the pistol? http://www.midwayusa.com/product/1485534582/ed-brown-mainspring-housing-flat-1911-government-commander-chainlink
I replaced mine and it was a real easy job (if you follow the youtube tips for not losing your spring) and it makes it look and feel like much nicer quality.