Here's a shot of Piranhatrons.

Here's a shot of the captured Zordon.

Here's Rygog and a Piranhatron.

Here's the Phantom Ranger.

Here's Quantrons and Astronema.

Here's Quantrons and Elgar on the Dark Fortress.

Here's the Megaship by the planet Hercuron.

Crocovile 1's point of view from the lake is new footage.
Here's a shot of Phantom Ranger and the Red Ranger.

In this shot, Phantom has the disc for the Delta Megaship.
The new footage starts as soon as the Rangers appear on ground level at Angel Grove Lake.
Here's new footage of Crocovile.

This is when the Sentai footage starts up, as soon as you see this shot.

The shot of Crocovile growing is Sentai footage but the Satellaser beam was added into the Sentai footage.
Here's a shot of the Red Ranger riding on his Galaxy Glider. This is new footage.

All Giant footage is Sentai footage however all following shots of Red Ranger riding on his Glider is new.
Footage of the Delta Megaship is Sentai footage.
All footage of Red Ranger inside the Delta Megaship is Sentai footage.
This shot of the Delta Megaship's Control Room Door is new footage as shown here.

but otherwise all other shots of the isnide of the Delta Megaship is Sentai footage.
There was a slight change in dialogue between what Phantom Ranger told Andros about the Delta Megaship's slots and what MegaRed had been informed about. Phantom didn't give any indication that the wrong slot would be danger but in Megaranger, MegaRed was informed that if he chose the wrong slot it would activate the Delta Megaship's self destruct program.
Here's Dark Specter and Astronema.

Here's a shot of Astronema with her Wrath Staff.

All Giant footage is Sentai footage. However the following shots of the 5 Rangers being back on Hercuron is new footage.

Following info comes from Mega 20.

Here's Crocovile 1.

Here's an exterior shot of the Astro Megaship however something is by it.

Here's a shot of Giant Crocovile 1.

Here's Giant Crocovile 1 and Giant Crocovile 2.

Here's a shot of Giant Crocovile 2.

Here's a shot of the CD that is needed for the Delta Megaship.

Here's the Delta Megaship.

Here's the Delta Megazord.