I just moved contents from my first TYPO3 site, a 10 years old TYPO3 3.5, to the new 6.1
It was 2003, 10 years ago!
Everything works like a charm!
If someone is interested here the “how to”:
Copy pages and tt_content tables from old site to new TYPO3 db (dump and restore with drop tables)
Copy uploads/pics uploads/media from old sites to fileadmin/pics fileadmin/media (or make a symbolic link from uploads/pics to fileadmin/pics)
Install tool -> compare tables to adjust all fields
Install tool -> migrate wizard -> Migrate all file relations from tt_content.image and pages.media
Install tool -> migrate wizard -> Migrate file relations of tt_content “uploads”