You can go to Rokor Files it has info on the SRT models. I know it was made 1966-1975. The first ones between 1966 and 1969 had a black shutter speed knob. The last SRT 101's got rid of the mirror lock up late 1974 or early 1975. I would say yours is a 1970-1974.
I just typed in Minolta SRT 101 and went to Camera Pedia. Go to how old is my SRT 101. From what I read yours is second generation. 1970-73. Also the serial numbers will be between 1643---- and 396---. I hope this helps more.