So essentially a normal person can just go through the class 3 NFA weapon procedure to buy this pistol? Is that correct? This isn't something I was too sure on since I've never bought or owned a class 3 weapon?
No, not a "normal person", because the Glock 18C wasn't around before 1986 and can't legally be transferred between individuals. Re-read post #3 - it explains who can legally possess them.