Are these sentences all OK?
You needn't have bothered to come so far.
If you'd let me known, I would've brought it to you.
If you'd called me, I would've brought it to you.
If you'd called me, I would've sent it to you.
If you'd let me known, I would've brought it to you. Wrong
If you had let me know..
If you'd called me, I would've brought it to you.
Correct
If you'd called me, I would've sent it to you.
Correct