Those were names of famous Belgian Pro racers from the 1930s and 1940s. I believe Marcel Kint, Rik van Steenbergen and Alberic "Brick" Schotte all held World Champion titles between the late 1930s and 1950 [Schotte in both 1948 & 50]. And, Sylvere Maes was the winner of the Tour de France in 1936 and 1939, [Schotte came in 2nd in 1948].

That handlebar was made by the Belgian company "TITAN", perhaps some time between the 1950s and early 70s. But, they were manufacturing bars and stems since the late 1930s. The heavy collar surrounding the stem clamp area was a fairly uncommon feature back then. It was not decorative, it was designed to ensure a strong and stiff alloy bar - very much a professional quality bar, and famous for being among the first early Dural alloy handlebars with no flex.

They were made in 25 mm diameter but also in a much larger diameter as well. If you measure the diameter near the clamp area I would not be surprised to find it is uncommonly large, around 27 mm. diameter. At that time a Cinelli bar measured 26.4 mm at the center, a standard British or US clamp was 25.4 mm (1 inch) and French bars had a clamp diameter of only 25.0 mm. So, this was a very serious racing component. It also required a TITAN stem - since they were the only company making one with a 27.0 mm. clamp diameter.

By the 1960s the Titan alloy bars were made with an unusual anodizing process which actually gave them a PINK color. This really did not strengthen them any further, it was really just to prevent corrosion - and to keep the hands and gloves from turning black (as they would from contact with any non-anodized aluminum).

The bend of many road racing handlebars were frequently copied from this original shape and would soon be referred to with the generic term "Maes bend" - after Sylvere Maes who may have helped to promote this particular curve.

Back in its day, 38 cm. was not at all considered a narrow bar width, it was as common as a 42 or 44 cm. road bar today. The Titan bars were available in widths from 35 to 42 cm. Titan was also famous for it's fine chromed steel bars and stems too. Many Track racers loved their steel track racing line, but even the alloy track bars were strong enough for sprinters to use, and this was very unusual for early aluminum alloy technology.

If you still have the stem you should probably save that as well.