The shot of the ocean's wave hitting the beach is Sentai footage but once you see Swabbies and Barbarax then that's definitely new footage.
Once Barbarax orders "Swabbies," it then cuts to Sentai footage of the Swabbies in the air.
These shots of Mutiny and his Crew in the Castle is all new footage

This shot has been edited. I do not know how MMPR Productions edited it but in Sentai, this shot had both Hyuuga and Kegler in it but they were both deleted from the shot.

These shots
is when the Sentai footage from Gingaman Episode 42 begins to play.
Any shots of Captain Mutiny and Barbarax being in the same shot together inside the Castle as they're overheating is new footage.
Also any shots of Deviot and Barbarax being in the same shot as Mutiny (who is in charge of the Castle's steering wheel) while they're overheating is also new footage.
Once Titanisaur lands in the water, the following shot of Deviot in the Castle is new footage.
Here's a new shot of a Swabbie within the Castle
Once Mutiny orders "Go Titanisaur and destroy Terra Venture," it then cuts to Sentai footage of Titanisaur swimming underwater which then cuts to new footage of the Rangers as they've received a page from Alpha. The shot of the Red Ranger calling for "GalactaBeasts arise!" is also new footage but once you see the GalactaBeasts again then it's back to Sentai footage.
This shot of civilians as debris continues to fall is new footage. Most instances of debris falling down as well as destruction scenes is Sentai footage. I'll only mention the instances of which aren't as obvious in regards to new footage only.

Sentai footage comes from Ginga Episodes 41 and 42