1930 Frau Schomburgk (GER)=Toni
The 1950 Belgian rankings included first names (From British Lawn Tennis and Badminton
Belgium (From Lawn Tennis and Badminton)
01 Mme Myriam Van Cutsem
02 Mme Marcelle Van Leer
This would appear to support your theories on Borman=Cutsem and David=Van Leer.
I discovered this little gem of a site just the other day.
http://www.tennisbelgica.be/
It yielded a vanue and finalist for 1902
[under entry for Beerschot]
For the first time in 1902,
the championships of Belgium took place in Beerschot and showing the victory of our player Miss Louise Gevers as champion of Belgium, beating in the finals Mrs. Comblen of Liège.
And a winners lists [under "Champions"]
Ladies' Singles
1897 Miss Madeleine Habets (T.C. Luik)
1898 Mad. Paul Trasenster (T.C. Luik)
1899 Mad. Paul Comblen T.C. Luik)
1900 Mad. Paul Trasenster
1901 Mad. Paul Comblen
1902 Miss Louis Gevers (Beerschot A.C.)
1903 Miss Jeanne Chazal (Léopold Club)
1904 Mad. Paul Trasenster
1905 Miss Marie Dufrénoy (T.C. Luik)
1906 Miss Marie Dufrénoy
1907 Miss Marie Dufrénoy
1908 Miss Marie Dufrénoy
1909 Mad. Jacques Chaudoir (T.C. Luik)
1910 Miss Marie Dufrénoy
1911 Mad. Paul de Borman (Léopold Club)
1912 Mad. Paul de Borman
1913 Miss eanne Liebrechts (Léopold Club)
1914 Mad. Paul de Borman
1915 – 1918 niet gespeeld
1919 Mad. Paul de Borman
1920 Mad. Paul de Borman
Gentlemen's Doubles
1897 Baron R. Rossius d’Humain and Nagelmackers.
1898 et 1899 pas joué
1900 Paul de Borman and Albert Lefebre
1901 W. le Maire de Warzée and Louis Trasenste
1902 W. le Maire de Warzée and Louis Trasenster
1903 W. le Maire de Warzée and Louis Trasenster
1904 Paul de Borman and Albert Lefebre
1905 W. le Maire de Warzée and Louis Trasenster
1906 W. le Maire de Warzée and Louis Trasenster
1907 Paul de Borman and Albert Lefebre
1908 W. le Maire de Warzée and Louis Trasenster
1909 W . le maire de Warzée and Louis Trasenster
1910 William du Vivier and georges Watson
1911 William du Vivier and Georges Watson
1912 Louis Trasenster and Réginald Storms
1913 William du Vivier and Georges Watson
1914 William du Vivier and Georges Watson
1915 – 1918 niet gespeeld
1919 Jean Washer and Victor de Laveleye
1920 Jean Washer and Albert Lammens
Ladies' Doubles
1906 Miss M. Dufrénoy and MissA. de Selliers de Moranville
1907 Miss M. Dufrénoy and Miss A. de Selliers de Moranville
1908 Mad. Jaques Chaudoir and Miss Marthe Trasenster
1909 Miss Lucienne and Miss Simone Tschaggeny
1911 Miss Renée Crabbe and Miss Jeanne Liebrechts
1912 Mad. Paul de Borman and Miss Luc. Tschaggeny
1913 Mad. Jaques Chaudoir and Miss Emile Dupont
1914 Mad. Paul de Borman and Miss Luc. Tschaggeny.
1915 – 1918 pas joué.
1919 Mad. Robert Grisar and Miss Josepha Diercxsens
1920 Mad. Réginald Storms and Miss Fernande Arendt
1921 Mad. Jaques Chaudoir and and Miss Emile Dupont
1922 Mad. Réginald Storms and Miss Armand Jamar
Mixed Doubles
1904 Paul de Borman and Miss Winnie Sorms
1905 Paul de Borman and Miss Winnie Storms
1906 Louis Trasenster and Miss Marie Dufrénoy
1907 Louis Trasenster and Miss Marie Dufrénoy
1908 Louis Trasenster and Miss Marie Dufrénoy
1909 Louis Trasenster and Miss Marie Dufrénoy
1910 Louis Trasenster and Miss Marie Dufrénoy
1911 Alph.Van Nitsen and Mad. Paul de Borman
1912 William du Vivier and Miss L. Tschaggeny
1913 William du Vivier and Mad. Paul de Borman
1914 William du Vivier and Miss L. Tschaggeny
1914 – 1918 pas joué
1919 Albert Lammens and Mad..de Borman
1920 René Laloux and Miss Emile Dupont
1921 M. van den Bemden and Miss Rob. Grisar
1922 Georges Watson and Miss Réginald Storms