I don't have the bike with me and don't know the serial number. The seller told me it was a '78, but I don't know for sure. Also, looking at your frame again, it doesn't have top tube cable guides (as does mine) so it could be a little earlier. But not much earlier--the early 70's bikes did not have brazed-on derailleur cable guides, so I would put it tentatively in the mid-70's.
Here's a photo of mine, refinished with Profesional decals. The fork crown on the Super Carrera is a bit more rounded, but it has the same lugs, dropouts, fastback seat stays, brake bridge treatment, and overall lines as the Competition. The SC was built with Tange n. 2 tubing, so the SP diameter is a bit narrower at 26.8mm. There were at least three models with very similar looking frames: the Profesional with Campagnolo Record, the Competition with Suntour, and the Super Carrera with Shimano 600.