Establishing intent is easier given that the obviously added last name of Moore is a very bad attempt to forge the script Moore uses to write his name
This is not some innocent annotation to memorialize who wrote the message, it’s an outright attempt to forge Moore’s signature by duplicating public examples of his signature found on court documents
Nothing at all innocent or legit
I’m inclined to agree that the main part of the inscription is a forgery, and the subsequent annotation in a different hand is intended to add a degree of authenticity.
Somebody needs to find a handwriting sample from the alleged victim.