You’re probably right that the slider pins were damaged in the fall.
I’ve been buying keyboard parts from Syntaur. They have what I think is the Axiom 61 version 2 board.
Here is the Axiom 61 version 1 board from another keyboard parts source but it’s not in stock:
Here is a youtube showing replacement of the Axiom 61 version 1 slider board (skip to 7 minute point)
BTW, I’m pretty sure the 49 key model has the same slider board but again different depending on version 1 or version 2.