What seems odd is that style Columbus decal came out circa 1978, and later mid 80s decals would specify the actual tubeset ("SL", "SP", etc.). That Cinelli BB shell would certainly be availble in the mid 80s (I think they made it available circa 1982). If the tubing is Columbus "GILCO" (4 flutes) it may be a bit later 80s. That tubing was developed in colaboration with Colnago and was first used on the Master and Arabesque models (correct me if I'm wrong) circa '84-'85. I believe that in its early days of use it was made for and used exclusively by Colnago. There are Columbus decals for the "GILCO" tubeset, one without any Colnago stuff on it ( "GILCO MS DESIGN"), but I am not sure when it was first used, nor when Columbus made that tubing avalaible to other builders. The general decal design changed by the mid 80s aside from having the tubeset specified ("wavy" lines). I would assume that a decal comes with the tubeset, but not being a builder I have no idea. It may have been that an older decal was used, or was mounted to replace an original decal.
Teresio is his first name. I have the Cicli Rozza name in my research list of Italian companies; also make the modern "Stark" brand. I would contact their shop and they should be able to give you more exact information on the year it was built. I have often contacted small Italian companies, and they are, for the most part, happy to help out; and are also pleased that their marque is being kept alive with early examples still being ridden about the roadways.
I have that Italian bike map; it is far from being complete. Especially relating to smaller builders/shops. It is still a very good resource though and I recommend folks get a copy. My list of Italian marques is at about 1000 entries.