Handsome-looking mid-80s 52 cm Benotto 2500 with Shimano 600 components. Can't find exact information about which Columbus tubing but likely SL? I understand that 80s Benotto's were not made in Italy but Mexico - still this seems rather on the cheap side for what it is and I like the paint job.
...that looks like a real possibility if it fits. Whatever the frame tubing (Columbus made many over the years) won't make a whole lot of difference (even if it's Aelle, which was seamed I think) The Mexican bikes I've ridden from Windsor (Windsor Pro) made from Columbus were every bit as fine a ride as similar ones made in Italy....so I would definitely go look at that one if I were you.
Shimano 600 from that era is solid, mid level componentry, and the indexing stuff worked better than anyone else's, including Campagnolo.