You will like the motor even more when you have it running.
the Black stuff is protective coating to keep the electrical connecting surfaces operational.
Our old Guru, now in boat motor heaven, ( Bob Hatcher ) always picket it out and saved it in a small tin can to heat up and reuse.
The original spark plug wire, was 9mm with grey rubber covering and very flexible wire.
Many people have used cloth covered old car spark plug wire which may be a little stiff when moving the spark lever.
The wire making process often tinned the bare wire before insulating and adding cloth cover and shellac coating.
DO NOT SOLDER THE SPARK PLUG WIRE TO THE COIL TERMINAL !
There is a lot more info but typing is so slow.
call and leave a message and then I could convey more info.
517-2six3 3 six six sis