Thanks for your reply, Lynne.
I would settle for the line between the Post title and the post content.
(I have tried your code, in your post above, in both postbit.css and additional.css, and it works in neither. I am using postbit). Is there anything I can add in my .css and would you be kind enough as to confirm which .css I add to it to, please?).
I would also like the space to be smaller at the bottom of the signature line - and that is it - I am happy.
But the most wanted one is the line.
Sorry for waffling on.
Many Thanks.