Mark - Seems like that might be a PR-10. In 1973 when I bought my first "good" bike, it was a PA-10. Cottered cranks and sew-ups! It was $150. The PR-10 was $200 and the PX-10 must have been $250. Way out of my price range. I sold my Hodaka Ace-100 motorcycle to buy it. Saw me through my first year of touring and club racing.
Bob