Yes, that's the problem, as they could just change the letters and because of the stupid confidential way they do it, I would never know that it had been agreed and then taken off me. All the board (in fact all senior members of staff) are men, and I could not rely on any of them to blow the whistle and tell me that it had been taken off me. So I just wouldn't know.
Been talking to some friends who work for similarly male dominated companies, they all say try and wait at least until the letters are written as then they would need to actually destroy something written down which would put them in the position of actively taking it off me rather than just changing their minds.
But now that a client knows and may tell, does it look deceitful if I wait? To be honest I can't believe no one has noticed either. I am not showing that much, but perhaps the lack of women in work helps, they probably just think i've eaten a few pies, and most of the blokes wouldn't dare say anythign for fear of offending! (Lack of women means most of them try not to meet my eyes at the best of times, female bosses are way scary!)