If looking just to walk old saves up from 19 to 26 try downloading the demos from 20 to 25 here (assuming you don’t have those versions).
https://www.ootpdevelopments.com/ootp-prior-version/
From the 20 start screen, no license required, you can navigate to the saved games in the 19 file structure and import them to 20. Then repeat those steps all the way to 26.