Based on the size and era, it is almost certainly Columbus SP tubing. I don't know if they had a model name for it back then, but it would eventually evolve into the Grandis Special. Double check on those wheels. I doubt they are 27". They should be 700C. A frame like that would have marginal clearance for 27" and you might lose some potential buyers if they key in on 27" wheels. While you're at it, you need to back off the front skewer nut a bit, so you can get full closure on the lever. Before you post the for sale pictures, also lower the saddle a bit. The excessively tall height creates an illusion that destroys the proportions of the bicycle.