Nigel:
for some more images of that sort of saddle clamp to supplement flecc's, go to Google, switch to Images, and search for bike saddle clamps.
There are other views of the same sort of clamp, which might give you more clues! All saddle clamps are a bit fiddly, and if you can assemble them OFF the bike (i.e. take out the seatpost, and take saddle, post and clamp to a nice flat table), it is easier.
A.
for some more images of that sort of saddle clamp to supplement flecc's, go to Google, switch to Images, and search for bike saddle clamps.
There are other views of the same sort of clamp, which might give you more clues! All saddle clamps are a bit fiddly, and if you can assemble them OFF the bike (i.e. take out the seatpost, and take saddle, post and clamp to a nice flat table), it is easier.
A.