Good luck with the rescue thing, I hope the weekend goes well.
The only real regret in life that I have is that I can't save them all, we have many healthy horses in hungary that go for slaughter, I have limited funds and limited acerage - even worse horse rescue over here is almost unheard of.
I hope that the good that you do outweights the bad that you see.
Having rescued a few myself I know how bad things can get, I also know the rewards.
I really do wish you well and I don't know how you keep your spirits up when there is so much that cannot be done.