Your frame has similarities to the RC4000 in the '88 catalog: https://bulgier.net/pics/bike/Catalogs/rossin-88/5.jpg - no chrome, cable guides, brake bridge (although I can't see yours very well.)

This '89 RC4000 also looks similar to yours: https://globalvintagemedia.com/rossi...road-bike-1989 - no chrome, cable guides, sexy BB cable holes, sans chainstay bridge, Columbus dropouts, fork crown, brake bridge, seat cluster, head tube lugs.

So possibly Columbus Matrix (aka Cromor) tubing.

Not totally convinced the decals/graphics on yours are original.