Hi Torben,
Currently there already this system in place. And you don't need OO to make it work. The basic way to get content in is to create an acs_object then a cr_item. After that create an acs_object then a cr_revision. The are also content repository api for this. You may also want to start reading the doc of content repository in particular the data object model page.
http://youopenacssite/doc/acs-content-repository/object-model.html
Then look at how file-storage or etp and study how it puts in content to the database.
As for getting it out its just a matter of selecting the cr_item and cr_revision. Or better yet use some Tcl API what DonB has wrote in particular cr_write_content. Its a matter of getting used to the data model and api, after a while everything will make sense somehow.
I hope we can move the code easier for new developers coming in.