I'd stripped Bike down completely during the week, and checked and serviced everything, polished the frame, then re-assembled.
Meanwhile, I'd fitted a 28t inner ring to my Campag Chorus Triple. The rings were 53/42/30, and now they're 53/42/28. This, coupled with my 12-30 Centaur cassette gives a sub unity bottom gear. First time I've ever been this low.

Basically, my 2nd gear is almost the same as my bottom gear was before, so all I've done is extend the bottom end.
The new Zircal 28t chainwheel came from Spa for £10 plus p+p. The teeth are a little thicker than the Campag rings but everything is sweet and the changes are fine. All in all, I'm quite pleased.
I think the Campag Comp front mech I use would manage a 26t even with the 42t and 53t, but I think 28t is small enough for now.