dddd

This model seems to be the exact same bike as the Nishiki Competition, which I owned.

This is mostly a good bike, the parts are cool and the frame/finish is attractive.

There is one issue, having to do with the wheelset. The 1970's stainless steel spokes as fitted to these models (and to Centurions btw) are extremely short-lived (prone to start snapping with regularity after ~1000 miles or so). It's a shame because the hubs and rims are what I would consider good parts.

The plain driveside dropout and the .833 steerer lead me to believe that the tubing specification is modest, but a weigh-in might answer questions regarding it's quality.

I have a 1973 American Eagle Kokusai model (which is a "Pre-badged" Nishiki International) that, like yours, has the Nishiki head badge.
So I'm guessing that yours is perhaps from the same transitional year. Mine is the same silver color, though lacks the rear frame's chrome plating since it is a one tier lower model than yours.

Check the back side of the front derailer cage or rear derailer body link, and look for the date code appearing as two capital letters.
Suntour began the 1st digit's alphabet with letter A in 1984, so counting backward from the letter Z as 1983 will get you the derailer's manufacturing date (the bike's model year will typically come some months later). Letter P would be 1973.
The second digit is the month (letter A is January, etc.).