I have both the Jaguar 70 and 75 and just found out about the 101 which looks like a basic 70 series but has an adjustable rear sight. The 101 that I saw has an adjustable rear sight at the rear of the barrel on what looks like a fixed "housing". I have also seen the 75 with the fixed rear sight taken off and an adjustable rear sight placed in front of the old sight.

Does anyone know how to find the "housing" to change over to an adjustable rear sight? If I took out the old fixed sight an put an adjustable rear sight on in front I assume a gunsmith would have to drill a hole on top of the slide to screw the adjustable sight down. Any thoughts?

Thanks in advance.