The S2s are cool cameras. There are almost no plastic parts on them, like there are on the later Spotmatics and SL. There was a later release known as the S2 super that had 1/1000 shutter speed and self resetting frame counter. Does your camera have those?
The 55mm f1.8 Takumar is a wonderful lens with great sharpness and very nice out of focus image area. I'm guessing yours is a Super Tak? This image if from an SMC Takumar 55mm f1.8, but rendering shouldn't be much different: