In 1979 there were both uncirculated and proof SBA dollars with an S mintmark. The 1979 S circulation issue was not included in mint sets. Only the P & D were included. This appears to be a circulation strike, therefore, I don't think the TY 1 or TY 2 S mintmark is relevant here. I am pretty sure the TY 1 or TY 2 is for proof only.