That's a sweet bike. Looks very clean.
I have one of these and have barely ridden it. Mine is original except wheels and FD. Someone put a Sora on it and the wheels are Weinmann.
I thought there was some sort of braze on on the DT for the original Suntour shifters? I could be wrong about that. I like the heart shape little bump under the DT to keep the shifter collar from sliding.