My dad just recently gave me his treasured Nishiki racing bike. He couldn't tell me much about it but I think it looks really cool and may want to restore it. I was hoping that someone could help me in determining more specific details about the bike but also give me some insights into what parts where most likely to have been mounted at sale.

The bike was purchased in Denmark hence does not reflect any of the serial number formatting presented here but I read some replies discussing how danish bikes were different in the numbering.
On the bottom bracket it says BT 2584 U just above the famous "N". Also, just above the serial number on the seat tube it says J47. Any ideas? From the numbering I would assume June, 1984 but don't know what the letters stand for. Any suggestions what a ´84 model would have had for components?

Thanks in advance