As some of you know... I got in a bit of trouble with the ATF like 4 years ago. There were some debates about how E-matches are regulated therefore requires a LEUP. Well when the ATF got me I had some oxrals and daveyfires (I made ejection charges out of them and they thought they were squibs) and I didn't get nailed on any of them... I even had a can of 4f blackpowder and again, no criminal charges on that either. I don't know if this means that ATF is just being a prick and trying to scare people into things or if they could really charge you with a crime if you had oxrals or 4f blackpowder for rocketry use. But in my test case, they either couldn't or didn't.
No I didn't have any antique firearms, only "modern" firearms (that uses smokeless powders) and I am sure if its illegal to have blackpowder without using them for shooting they probably would have given me that. That's not to say that the ATF wont give you administative trouble though, it just means they possibly cannot give you a criminal charge for having E matches/bp around.
I dont know what changes the Safe Explosives Act did however so dont flame me for it.