Your sights are the same as these. W. German P230
My P6 was made in 1980. I was at a shoot a few tears ago that Sig sponsered.
One of their reps was watching me shoot a Cetme I had at the time. He was picking up brass and commenting about the fluted chamber marks stating it had to be a G3. Well it was not. He was still amazed at what it could do. I pulled my P6 from its' holster and handed it to him. He had never seen one. He did however tell me what the groove in the hammer and other interal parts was for. An easy way to check in the feild what is wearing and what needs to be replaced. A feeler gauge, similar to what you use to set plugs or points on a car is used. Great day overall.