Hello @
ziebak, welcome to the forums. Can you post some more pics and information? It looks like some of the components are 105SC but I can't tell about the brakes. What is the headset? (HS) Do you know the bottom bracket (BB) shell size? What does the tubing decal say? What is stamped on the dropouts?
Can you post a pic of the fork crown, seat stay caps and dropouts? Where is this bike? U.S., Europe, Canada?
I don't recognize the paint (looks home made highlighting or something is it over the decals?) but the decals could make it somewhere around '84 to 87 but the 105 SC is newer than that.