For Arthur George, according to the birth certificate, he was born in Marchienne-au-Pont in the Belgian province of Hainaut on 1881-07-14 (the certificate itself was filled out on the 15th). A digital copy of the birth certificate is available online from the Belgian State Archives. https://search.arch.be/en/zoeken-naar-archieven/zoekresultaa...
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According to the birth certificate, the parents of Arthur George are cited as Séraphin Joseph George (age 33, chauffeur/driver) and Marie Thérese Delval (no age cited).
I checked the 10 year table of marriages for Marchienne-au-Pont but unfortunately there was no record of their marriage between 1851 and 1880, so they must have been married somewhere else.
In terms of the Dehoux children, do you have any idea where they were born? The way the Belgian archives are organised is by municipality, so without knowing where, you are at the mercy of having the records indexed by name (which I also checked but with no results).
Sorry that I wasn't able to find more for you, but I hope this helps.
Regards, Dave Schoonaertdave.email@example.com