Hi Tango,
that scoring itself is not a big story.
Maybe it had touched the outer metal ring of the inner coil.
It is all very tight in there and within the mechanical production limits at that time (37 years ago!) it might happen.
You may check mounting position of inner coil to correct that.
Unscrew just a little bit, move it a bit within its limits and tighten it again may help.
Cheers, Michael
