Cody, you got a GREAT deal on you Royal! $5 dollars for a machine that's only 4 years old, you practically stole that Royal. The correct bag for your Royal would be the orange bag that's on current models.
If I was you, I would get the shake-out bag, though. Why? Because the shake-out bag has the black top-fill tube inside....this allows you to use Royal Style B bags if you wish, or you can use it as a shake-out bag, & you have more versatility. It also has the benefit of not having any zipper to replace- just slide the clamp off to change your bag or empty it, & it also costs a few bucks less than what you will pay for a zipper bag. Try to find a good second-hand one on Ebay, though....Royal bags are VERY pricey to buy new from a dealer. The zipper bag costs just under $125 CDN when I checked earlier this year.
Have fun with your new Royal, Cody!
Rob