Find the difference! (Part 2)

Find the difference! (Part 2) -- Perhaps it's the coloring and the front; the two trains look very similar, yet not identical. The 420 series on the left was made in 1927 by Carminati & Toselli in Milan, while the 109-110 pair on the right in 1941 by Casaralta in Bologna. -- Rome (it), Centocelle, 6 March 2025, 16:53 CET