Was the original site created with Power CMS?
if so then the content will be in the pcs2_contents table.
you could export that table from the original site and import it to the new site.
you will probably have to edit the old page and change the require once code to link to the CMS files and change the paths.
any images that where in the CMS will probably need to have the paths changed too.
if you need assistance with this, I suggest signing up for a premiere support appointment: