Everything within Tommy's dream would be Sentai footage. It along with the Monster of his Dream (Squidrose) originate from Abaranger 28.
Everything within Kira's dream is Sentai footage including the Crocodile Monster.
Not sure with these shots   but this is Sentai
I believe this is new
Here's Sentai footage of the Monkey
Looks to be new
Sentai
This could be new but after checking over the episode, this shot of the Blue Ranger is actually Sentai but once you see the Brachiozord is when you are seeing Sentai stock footage. These shots are something that I do not know about  
Here's definite Sentai footage of Rude Elf



NOTE: Tommy's dream features Sentai footage from Abaranger 28.
Kira's dream features Sentai footage from Abaranger 21.
Most of the content in Ethan's dream as well as all footage of Rumba Monkey is Sentai footage and it comes from Abaranger 45.
Most of the content in Conner's dream as well as all footage of Rude Elf is Sentai footage and it comes from Abaranger 41.