It is quite tricky to locate immigration records in the UK (especially for people from Europe) unless they became citizens.
https://www.familysearch.org/ does have, not name indexed though, Belgian records: go to "Europe" and look for "Belgium Civil Registration".
You want Hainaut and then Tournai - the images aren't coming up at the moment for me but they do seem to come and go so check again later. There are birth indexes and birth records for the period of interest.
His marriage (I presume this data is from the Catholic parish records of the marriage, as normally this info wouldn't be given) is also indexed on that site, giving his mother as Anastasia Lardez.