WordPress blog merging advice needed

[tamjl]

I'm hoping someone here can give me some "best practice" guidance on merging several WordPress blogs.

Here's what I plan to do and the questions I have follow:

1. I have a site, we'll call it SITE.
2. I have two blogs in other locations, we'll call them BLOG A and BLOG B.
3. BLOG A and BLOG B each have their own Feedburner feeds.
4. I want to bring BLOG A and BLOG B into a single blog on SITE.
5. I will then eliminate BLOG A and BLOG B as stand-alone blogs.
6. I will set SITE's new "unified" blog to use the Feedburner feed from BLOG A.

Here's the catch: I don't want any subscribers to BLOG A's feed to get a flood of posts from the newly combined feed on SITE. They'll already have seen almost all those posts and I don't want to irritate them.

Can anyone advise me how to do this so that the feed doesn't send out "new" posts that really aren't?

Thanks!