I've just found out that the complete four seasons will be released on DVD on October 9, 2009. You can pre-order on amazon.com but not on amazon.co.uk. This news made my day. I can't say how much I love this show.
I remember watching this in the mid-80s when it was on UK TV. It was genuinely funny, warm, and innovative, even if Garry's teeth and hair were a little unusual for UK TV. A few full episodes were briefly on youtube a couple of years ago, but now they're gone. The only other time I've found it was when I spent a snowy afternoon in the Museum of TV and Radio in NY and you get to watch a couple of hours of video of anything in their archives. It was great - I watched four episodes back to back, and was transported. Worth the ?$10 admission.