National RX-C45 sound and the tape mechanical problem

Do you have a National RX-C45 book?
Someone give me that boombox, but it has some problem like: only right speaker loud on radio mode, and the tape mechanical is not working properly and also 2 transistor missing on the pcb and the fm stereo led didn't turn on. And I didn't know the code of that missing 2 transistor. I want to replace it, but how to know the code.
I hope you can help..