Once you see Chillyfish then that's the start of Sentai footage.
Any scenes that you see the Terra Venture Vehicles in, that signals new footage since you never see those kinds of vehicles in Gingaman
The shots of Chillyfish's chill spike lasers getting the cars by the traffic light is back to Sentai footage.
The shot of the puppy by the civilian is new footage.
Once you see the Red Ranger then that's another start of Sentai footage.
This shot of the Red Ranger fighting Chillyfish is when it goes to new footage.
Here's another new shot
Once you see Chillyfish again then that's when it goes back to Sentai footage.
These shots
is new footage, the attack had to be reshot since in Gingaman it went at his neck.
This shot of the Red Ranger is when it goes back to Sentai footage.
Once you see the Chillyfish Saucer Head then that's another start of Sentai footage.
All Venture Vehicles will signal new footage. This shot of the Chillyfish Head is also new footage

Here's Leo in the same shot as Stingwingers, Trakeena and Treacheron
Here's new footage of the Red Ranger with his Transdagger while he's in the middle of fighting Treacheron as well
All footage of the Red Ranger fighting Treacheron is new footage.
Here's new footage of the Red Ranger and the Magna Defender, in this shot Magna is holding a box
These shots
  is when it goes back to Sentai footage.
Once you see the small chest item again then that's back to new footage.
This shot of the fake Lights is I believe Sentai footage, it then cuts back into new footage of the Red Ranger and the Magna Defender
The black rabbit is also new footage.
These shots
is when it goes back to Sentai footage.
Chillyfish grows in the usual Sentai growing sequence way. You never see him drink the Potion in the episode but in Sentai you do see him drink the Potion
All footage of the Lion in the zord battle has been cut out.
The footage of the Red Ranger on his GalactaBeast which is shown on the Megaship Viewing Screen is actually Sentai stock footage.
All Giant footage is Sentai footage.
The next time you see the Magna Defender on the ground it's back to new footage.

Sentai footage comes from Ginga Episode 20