Using book_copy to clone a book full of projects and cases results in a new project, but all cases still on first project.

I realize this might be an odd setup... but I'm in a situation where I need to create project 'templates' and replicate large 50+ case projects at will.

What I've done to achieve this is set up a project as a book, with the project as the first page, and cases are nested below as milestones, and tasks below those.
This results in 5-6 different types of projects we use regularly at work, that we can pull out and slap a new name and date on and get going at will.

Using node clone only lets me copy the project, and doesn't include the cases associated to it.
book_copy is an extension of node clone, which lets me copy the entire book.

A second project is created, and its properties seem to be unique (it has the same title at first, but i can easily change that)
The cases underneath it get replicated into the new book as well, but their properties still point them to the original project.

If I go view all related cases to the first project, it now looks like they have all been doubled.
By going into book view and viewing the new (cloned) book, I can see the cases which should now be part of the new project.

I can manually go through all these cases and change the project assignment, but this is extremely tedious for projects with 50+ cases.

Is there an easier way to accomplish this level of creating 'templates' which I am missing?
Or perhaps an easy way to update a whole group of cases at once? Would be nice if I could select all the cases in a book and update them with a couple clicks.

At present this is the only issue holding this site from going live for us, I'm stumped as to how we can easily accomplish this without 1-2 hours of manpower to set up every new project.

ALSO: The person assigned to each case gets stripped out when I copy the entire book. All cases get assigned to the 'default assignee' but still maintain all other fields.

Any help you could provide would be greatly greatly appreciated, I've been stuck on this for a little while now :(