Here is where it definitely goes to Sentai footage
Sentai shots 
New footage
This shot of the Stego-Plate on Blue's Morpher I believe is new footage as well
Here's a back to Sentai shot of the Stegozord
Jade Gladiator in the Island Fortress  
At this point in time, the shots of the Giant Jade Gladiator that play on the Monitor, I do not know whether it's new or not.
Here's new footage of the clone
Clone's Super Dino Mode which is also new footage
Sentai City Set from 42 and Giant Jade Gladiator from Sentai 42

These shots are Sentai but they are the first shots that originate from Abaranger 43  
Theese shots of the Brachio Morpher is when it goes back to Sentai  
New footage of Black Ranger as he's falling down after being forcibly ejected from the Dino Stegozord cockpit  
Sentai footage of Jade Gladiator in his "Plant-like" form
Also new footage, this time of White Ranger's Boots
Once you see Trent as White Ranger entering into his cockpit via the Dragozord is when the Sentai stock footage fun begins.
Once you see the Thundersaurus Megazord is when it goes back to regular Sentai footage.

NOTE: All Sentai footage which consists of all Giant Jade Gladiator footage as well as all footae of Deadwood and Skortch in this episode originates from Abaranger Episodes 42 and 43.