Very nice looking bike, looks like no one has messed with it except to replace the stock exhaust. This is not unusual as the stockers tended to rust through pretty quickly unless meticulously maintained.
You don't say how many miles are on it, but these bikes would go 100K miles on just routine maintenance easily. If it is at 16K miles or more, you should have the valve clearance checked and have a look at the cam chain tensioner.
These air cooled engines are noisier than water cool motors, so expect some clatter from the engine. Also, all the air cooled motors from this era have a distinctive smell when hot, it is normal. I don't know how to describe it, but my 81 CB 900 has it, my old CB 750 had it as well. My 96 Kat has it but the Suzy is a little different odor. They also make little snap crackle pop noises while cooling off.
I'd go for it unless it has a horrendous number of miles on it, if the engine is in as good of shape as the rest of the bike it is a steal. In my part of the country these bikes are becoming collector's items (or were before the economy sh%t the bed.
Glad it isn't around my house, I would have to buy it, then the missus would have my head on a plate. Don't wait too long or it will be gone, gone gone.