Here's an interesting one.

Serial number: A on the left, Z 2448 on the right side. The frame seems to be custom size between sizes 57 and 58. It is stripped of paint and the seller claims it weighs 1872g for frame and 761g for fork. It is advertised as Columbus SLX (Pro). Due to frame weight, could this actually be a 753 frame? The seat stay cluster is narrow like on Grand Prix and (standard) Strada. Pictures below.