PanAm is not, in and of itself, a Part 121 school, since they're not themselves an air carrier. Air carriers use their facilities to conduct Part 121 training, but that does not make the school itself a 121 provider, therefore any training received at PanAm OUTSIDE of air carrier training is Part 61, just as your paperwork says.
Now, there is nothing in 61 that says that maneuvers are identical to 121, I was only saying that they MAY be identical. What you might be able to do is talk to PanAm about getting a copy of one of their carrier customers' type ride grade sheets, and if the maneuvers thereon are substantially similar to what you did on your ride, it's POSSIBLE TransCan will let that fly (pun fully intended).