I have gone through some hoops to register on Single Track World to make a reply to this valuable thread. C&B Seen used to be OK – a good UK warranty on mediocre imported lamps, delivered with personal customer service. Unfortunately things have changed, probably because the company was bought out, and my guess is that the new owners are unwilling or unable to maintain it to the same old levels as Roger, the original owner.
I am so keen to record my experience for other buyers that I have written it up at length here: https://blog.jondh.me.uk/2019/10/the-woes-of-owning-cb-seen-cycle-lights/. For the record I have no hidden financial interest in a competing company, I just want to make potential customers aware of potential problems before they commit their money.
I am now the happy owner of a Exposure Race, and although it is 4-5 times the price of a cheap Chinese import, I am resigned to the fact that one gets what one pays for.