I purchased one missing the rear sight the firing pin safety and spring located under the rear sight. I purchased these parts from Gun Parts Corporation or Numrich and installed them. This gun is similar to the Officers versions of the 1911. It uses the same 6 round single stack magazine most 1911 officers models use. It is not the subcompact or I believe micro size Llama. My problem is after installing the firing pin safety, spring and rear sight the hammer will not drop, take the parts out and it drops. Is there a part I am still missing? What do these parts do? Thanks for your input.