I believe that most of the W Richards marked guns made in Belgium were low-end Pieper made guns, though not 100% positive. My uncle had one of these Belgian made W Richards & was carrying it about his arm one day & stopped to work on a fence. He laid it on the ground & when he finished work he forgot he had it & left it. Didn't discover it missing for a few days & thought it had been stolen. About a year later he stumbled across it, but it was of course totally ruined by then.
He also had my Grandfathers W Richards which has Birmingham proofs. It appears to have been built by J P Clabrough & Bros. I now have this gun as well as the "parts" of the Belgian one. The Birmingham gun is an older gun than the Belgian. Although a long way from a "Best" it is obvious it was a higher quality gun than the Belgian.