If it's a Umarex 1911 I believe I'm the only manufacturer of a full range of high quality aftermarket parts, have a look at my products page -
http://www.magic9designltd.com/home/product-range
There are a couple of photos of complete pistols, and a 1911 parts prices page, I'll be adding a page for finished photos of customer guns in the near future, if you don't see what you need I do offer a full bespoke service and can quote for anything,
Regards,
Nick