Here's Porto, Divatox and a Piranhatron
Here's new footage of Mad Mike  
Here's new footage of Mad Mike in Angel Grove  
Once T..J. and his 4 teammates Shift into Turbo then the scene cuts to Sentai footage of Mad Mike's beginning.
It looks like the "Stop" and "Start" buttons on the cooker are Sentai footage but they zoomed in on the footage and they edited the American text into the footage due to Japanese symbols being clearly shown in the Carranger episode.
This shot of Mad Mike is when it goes back to new footage however once the torpedoes land and they explode with sparks coming out, after the torpedoes explode with sparks, you'll then see it cut to Sentai footage of Mad Mike growing.
All Giant footage is Sentai footage and it was 1 of the rarities with Giant footage since it was fully intact.

Sentai footage comes from Car 27