In TPM there is a shot of the crowd and a shot of Sebulba at the start of the race that were cut for the DVD. Also, the transitions during the brief extended speeder trip after they reach Coruscant are different. Both these areas don’t exist in HD. The earliest HD broadcast is of the DVD version where these changed were first made.

In A New Hope, the speeder entering Mos Eisley, the Greedo shooting scene, and Jabba the Hutt were all changed for the DVD.

You may be right about Empire.

In Jedi, the only section I can think of is the end Celebration where they added Naboo and changed Coruscant.

All the other changes between the 97 SE versions and the DVD/Blu-ray can be pulled from the 35 mm scans.