I'm not sure of the executive order number. It's a fact because I got a DSP-5 RWA'd last Fall that had a MN 91/30 sniper rifle on it. I had to remove it and submit it again.
The $100, ($500 to Canada), exemption is for Category 1(a) firearms only. Non-automatic and semi-automatic firearms to caliber .50 inclusive (12.7mm).
The Form 6 import permit requires attachments from the seller and can be shipped at any point once it's approved. I've never heard of the 60 day thing.