Hi,
Over lunch time, I was talking with the owner of probably the oldest bike shop in Brussels.
He confirmed me that the original Van Hauwaert was from Brussels and that the name was bought by another shop from Renaix (Ronse) that initialy continued with 2 locations until he closed the Brussels one.
I was advised to visit the current VHW shop (about to close according to him) that has a micro museum, and to try to get in touch with Mr Devisscher.
(For the pictures, I asked an autorization)