Try Simon Goldsmith in Bristol, he may be more local to you than J H Steward. Simon works at Bisley a couple of days a week for J H Steward, he did me s shooting lens when I lived in Swindon as Bristol was closer than Bisley I popped over to see him there. For you it's a treck down the M5 but it definitely isn't as far as going to either Bisley or South Wales. Bedford may be your closest though, suppose it depends where in Walsall you are.
http://www.simongoldsmithopticians.co.uk/