We need to recreate list of most referenced pages and then make sure we continue them or provide equivalent content on the new site. Ann to define the process for this.
For now, the solution at launch will be to provide a link to the old site.
I am changing this to a phase II activity -- migrating completely off the old site should be an objective of the next implementation phase.
Comment: Please be relevant, civil, non-commercial.
I think the process is
I think the process is very simple. We have links to the whole site (except the first page) so everything can be found, even internal search will work. We will have links from some new pages to old pages (mostly ones that we intend to import but haven't yet).
The front page is omitted because we are not going to maintain it and it will quickly become missleading.
As we import stuff to the new site we will have fewer and fewer links to old pages. Also after importing we will fix the old site to point to the new pages (not as hard as it sounds because mostly we will import whole directories so we only have to replace the index.html page.) Only old pages with many links will be messy. However search engines will also have lots of stale links that will find old pages. These die out when they are no longer pointed to and can be killed quicker by deleting everthing but the index.html page from a directory. Then the search engines will get not found (but should be finding the new pages because we imported the now deleted info.)