Hi Jemma, I'd love to take this on for you.
There is more info on me, my work and experience on my profile page, so won't bore you with the spiel. If you have any further questions, just let me know.
To answer your questions...
I've had a quick look at the drawing you have provided, although can't get it to open Photoshop... It seems to be cut off half way down, maybe a corrupt file? Anyway... I'd obviously need to have that for reference.
I'd be hoping to get it done in around 7 days. I've doubled that on the proposal to be on the safe side.
In regard to revisions... I'd just want to carry on until you were happy that you had what you want. That being said, if it is being revised by committee, it generally works best if everybody has thier say and agrees before making further changes :)
I'll be able to start this weekend and would hope to have it back to you for revisions the following weekend. (possibly a day or 2 sooner, depending on how well it goes).
Okay.. hopefully hear from you soon.
Thanks, Karl