The competition model was one down from the top of the line in the 1979/80 years, and was a PK10, the replacement for the PR10. The three main tubes were Reynolds 531; check for a 531 sticker of the remeanents of right above the downtube shifters. However, the cottered crank and the low run of the rear brake cable sound like a lower end model. These would likely have a carbolite 103 sticker in place of the Reynolds, given the era. A picture would be massively helpful, as the description at this point is somewhat confusing. A PK would be identified as such on the serial number sticker at this age, so it's prolly out.