Hallmark is no longer in business.
That's the bad news, according to TMP:

http://theminiaturespage.com/man/?id=noble

The good new, also according to TMP is that NobleMinis has taken up their slack.

http://nobleminis.com/

It looks like it's a US operation now, and that UK-ers must go to a stockist.

This link goes right to their 1/6000th page. (whoops forgot the link, had to edit!)

http://www.nobleminis.com/Figurehead/Figurehead6000.html

I ordered some 1/285th infantry from them earlier this week and they haven't arrived yet, so I can't give you an opinion about their service/punctuality.  Even if I could, it would only be from one experience.

--Tim