CDM 22 pistol

I recently acquired a CDM .22 short pistol model #CDM serial # 19571. My dad found it hunting 20-30 years ago. The revolver will not turn when the trigger is pulled, which seems to be common with what little bit of info I can gather about these guns. I took it apart trying to figure it out on my own and I believe there is a broken part. Some of the parts just fell out when I took the trigger assembly out. I an under the impression that this particular gun is worth very little, but I was wondering if parts can be bought for the gun. I did not want to sink a lot in a gunsmith if it was something I could fix myself