drum brake piece

[Aurelio Landeros]

hey guys so i was looking at my frontaxle and on my driverside brake drumb there is a little oval piece missing where a brake line is supposed to go to any cllue n what it is and if i can use my old brake drum. i have my old rear and front axel i perchased another trucks frame (same year 70) ant it came with the rear end and front axle ect. that was the only little piece missing.