They make it harder and harder. You at a minimum really need a storefront any more. There are ways around this, but these are not the easiest things in the world to get. I thought about it years ago, but never wanted the additional scrutiny that they put on you. I like my privacy, I guess. If it's what you want, go for it--just know you are under a microscope and need to keep fairly detailed records.
Collector/Curio license isn't quite what you need for modern firearm stuff. It's limiting.
If you look on ATF.gov I am sure you can find a lot more details. If you want some phone numbers, I am sure I can dig some up for you, too.