Highly probable made with Columbus Aelle tubing. Accordingly the blue frames used it and the red frames likely were Columbus SL.

(Theres also variants of Aelle tubing such as R denoting dbl butted and another as Tre Tubi which was a blended tubeset of other Columbus tubing. )

Original decals are available. These are enjoyable bikes and less often seen. Intesting history that's worthy to read up on, especially of Othon I and his son.