That Columbus decal was used for both SL & SP but based on the size of the frame SP is most likely. Most builders converted form SL to SP somewhere in the 58-60cm range. The Columbus decal style also indicates pre-1988 while the Tommasini decal style is that introduced circa 1984-1985. It also looks like you're running 6 speed, so I'm assuming 126mm spacing, which would also fit the timeline. If it were 1990s, I'd expect 130mm spacing. The best I can say is that it appears to be circa 1984-1987.

The Racing model is very hard to nail down, outside of the fact that it is Columbus SL or SP. In the mid-1980s, it appears to have been the economical SL model, as it typically lacked the front derailleur of the Prestige. However KD has a Racing which appears to be circa 1982-1983 with this feature. What is curious about your sample is the use of internal brake cable routing, which is an expensive feature. Also, the ports are on the lower side on the top tube, All the others I've seen have been on the top side. I would have thought the money would be better spent on a front derailleur hanger and dual bottle bosses. I assume that all the variation we see is due to the variation in market preference or custom orders.