Thanks for those replies! Petra, I've pmed you, thanks. Astro-nutt, as far as I'm aware, Zac has had it completely stripped and re-assembled. The problem is that when we received the scope, the focuser was completely rusted up. It took a lot of work just to get it apart and it seems to have lost tolerances, hence the play. I haven't fiddled with it myself so this is just what I understand. Shimming improved it but it's still pretty woeful. It's such a big diameter barrel that any play gets magnified enormously - a very strange looking beast!
Anyway, still looking for a focuser for an 8" if anyone can help - thanks!
Cheers -
Rob