Yep no power to be made removing the baffle. It will just be obnoxiously loud and raspy. Ebay sells used ones alot of times cheap. I paid 100 bucks for my hmf slip-on. And found the header for 75 a few years later.
Just drilling some holes will help. You will need to increase the main jet one size if you open it up enough. Remember you can open it too much and just make more noise and loose some low to mid range power.