I have been querying a MS off and on for about 6 months and have gotten some reasonably positive responses including a full, a partial and critiques from a few agents. I took all this into consideration and decided to do a major rewrite. I'm also changing my MCs name and the working title.
I also think my query letter didn't work well so I'm rewriting that, too. Do I need to mention that this is a rewrite? And, can I send this to agents I have already queried who have rejected me?