Ok - I am going to bite the bullet and upgrade from 5.6.2.1 to 5.7 . I have read quite a few of the posts about the upgrade process in the forums and I am honestly not feeling that confident about the process.

Here are my issues:
1) My theme for my site is based on a old version of bootstrap that is no longer supported. Hostco, which created and sold the old theme in the marketplace, does not seem to have updated the theme for 5.7.
2) The site contains data on hiking trails. The data on each trail is contained in a series of relational tables that reside in the concrete5 database. I have built a series of blocks that query the databases and populate the various pages in my site.
3) My site contains hundreds of photo galleries. The site was originally built in another system. Trying to migrate the photos into the concrete5 file system would have been a nightmare. There are also a number of other sites that display files from my site, so renaming all these files would have resulted in tons of broken links around the web. Instead, I have created directories under the /files/ directory for my galleries. I have built blocks that programatically grab the photo files based on XML files and then populate the galleries on my site.

I am trying to figure out the best way to move forward. It seems like the first step maybe to upgrade the theme of my site in 5.6 so that it is compatible with what is used in 5.7. Any suggestions? I understand that 5.7 is now using a version of bootstrap.

It is not clear to me if the new version of concrete 5.7 still uses a /files/ directory so that I can simply move my galleries after the migration process. Possibly I should move the files to a new directory structure within concrete5.7 to reduce future migration problems?? Any suggestions? (I understand I may need to do some modification to the blocks that drive the galleries.)

I do not know how I should handle to database issue. I doubt the migration tool will handle this unique situation. Does the migration tool move/modify the concrete5 database? If so -- should I simply run the tool and then move by proprietary tables to the concrete5 database manually? Again, I understand I may need to make some changes to my blocks.

I will mention that the site contains hundreds of pages that are well indexed by search engines. The URL's for all the pages need to remain the same. As such, rebuilding the site from scratch would be very time consuming.

Any advice would be sincerely appreciated.

Thank you.