Eyesac on Lothor's Ship
Start of Sentai footage
New footage of the Navy Tsunami Cycle
The footage that plays on Cam's Super Computer Monitor involving Eyesac is new footage.

More new footage since for one thing, Eyesac was only Giant-sized in Sentai and for another thing, in Hurricanger, Motodrone and Eyesac were actually the same being.
More new footage

Scroll of Empowerment doing its business on Earth is the usual Sentai stock footage.
However then you will see a flash of light and then you will see new footage of Eyesac as a Giant  
Also new footage, there's no editing trick involved here to make it seem like Eyesac was just edited into the footage from another shot
Once you see the Storm Megazord that is when it goes back to Sentai footage.
Here's Storm Megazord and Eyesac doing battling while Dustin and Tori in Ranger form are on the Tsunami Cycles on the rooftop Now the shots of the Blue and Yellow Rangers riding the Thunder Tsunami Cycles are new footage but those shots are edited into the Sentai footage.
Back to new footage
Back to Sentai 
For some strange reason they changed the color of Eyesac's destruction explosion so that it wouldn't be a purplish pinkish color instead of the more proper fiery explosion. Eyesac's explosion is not new footage, it's Sentai footage but they just changed the color of the explosion for whatever reason.
This shot of the Megazord Cockpit originates from Hurricanger 44

NOTE: The training system with Tori and Shane riding the Tsunami Cycles originates from Hurricanger 36.
Some Giant Eyesac footage originates from Hurricanger 37.