The first one they used a Poulan 306A, the second one they used a Dolmar 100something series, probably a LARGE 120super with silver paint on it, a homelite XL2, a Mac 120, and a Husky 61Rancher. the third one, they used I think a Stihl 038 with some chrome on it, the 4th one a McCulloch Pro Mac 10-10, the newest one, I believe was a beat up Husky 357Xp.
I've got all of the movies, so I can tell you because I've watched em REPEATEDLY, just to know what models they used.