Jose,
Thanks for the pictures.
Copper line is not original, should be white or black 1/8" nylon with cone type ferrules and sleeve, but at this point I do not know which one is correct for early 67 L78 with firewall fitting.
Mike S has an 325 HP 05B with firewall fitting and it has white lines and fittings which I believe to be correct for early version oil lines.
No correct information on early L78 version system just bits and pieces.
If your copper line has barrel ferrule and you use it with original gauge and adaptor you will have and oil leak.
Bob