Have just sent a drawing,with explanation, to Simon Miller who kindly agreed
to have a look at what I've come up with so far. If anyone else would like
to review it, could you send me your email address (you can reply to me
directly)?

Alternatively, I could post it here with the drawing (jpg) attached, but am
unsure how this would be received by the members of the newsgroup (wouldn't
want to **** anyone off). The jpg is only about 48KB, but if you've got a
slow connection, and you aren't interested, it would just be a pain.

As ever, any comments and suggestions would be gratefully received.
Grimble