The same attorney updated his summary in response to questions on the Knifetalk Forum:

"As further comment on the new rule, which takes effect July 6, 2016, I offer the following summary:

SOURCE OF IVORY
-The new rule applies only to ivory from African elephants.
-Rules regarding ivory from Asian elephants are set forth under the Endangered Species Act (very strict; antiques only).
-Rules regarding ivory from walrus, and other marine mammals, are set forth under the Marine Mammal Protection Act.
-See also CITES which has rules regarding use of/commerce in ivory.

OWNERSHIP/POSSESSION
-Non-commercial ownership, possession, use, transportation (within the USA) and display of African elephant ivory continues to be allowed so long as the ivory was "lawfully acquired". The new rule does not change the existing rules in this regard.

INTRASTATE COMMERCE
-The new rule does not impact intrastate sale/commerce of items containing ivory.
-CITES "use after import" provisions/restrictions do apply to intrastate sales.
-Some states have passed laws which restrict sales/commerce in ivory. Sellers should check their individual state laws.

INTERSTATE COMMERCE
-The new rule does impact interstate sale/commerce of items containing ivory.
-As of July 6, 2016, no interstate sale/commerce in items containing ivory is permitted unless the item qualifies under a specified exception.
-For purposes of an ivory handled knife, the relevant exceptions are: (i) the ESA "antique" exception (which has several criteria, including that the item be at least 100 years old); and (ii) the "de minimis" exception.

DEMINIMIS EXCEPTION
-The "de minimis" exception has several criteria, all of which must be met (see list of criteria in earlier posts).
-The first, and what will probably be the most difficult criteria to meet, is to demonstrate that the ivory was imported into the USA before January 18, 1990, or that it was imported under a pre-CITES certificate.
-The seller has burden to prove that that the ivory was legally acquired, and that it meets all other criteria including total weight; % of weight/volume; value; and date made. An ivory handled knife is presumed to meet the weight criteria. It will not be necessary to remove the handle to be weighed.
-To qualify under the "de minimis" exception, the item must have been made (handcrafted or manufactured) before July 6, 2016.
-This made before date certainly sounds like the death knell for interstate sale/commerce of ivory handled knives made after 7/6/16.
-The new rule is absolutely the death knell for interstate sale of non-antique items primarily made of ivory, such as an ivory chess set, a elephant tusks (or other raw ivory), or an ivory figurine. Musical instruments have different rules and are not discussed here.
-Makers can make elephant ivory handled knives after 7/6/16 (assuming that the ivory was legally acquired), but cannot sell them via interstate commerce.
-What if I make an ivory handled knife in TX on 7/7/16, go to the BLADE Show in GA, and sell it to a buyer there? The feds would consider such a transaction to be interstate commerce (and in violation of the rule).

CAN I LEGALLY SELL MY IVORY HANDLED KNIFE AFTER 7/6/16?
-The short answer is, it depends...
-Yes, you can sell it within your state, if CITES and your state's laws permit the sale.
-Yes, you can sell it via interstate commerce, if it qualifies as an antique or it qualifies under the "de minimis" exception, and you can prove that it so qualifies (you will need paperwork demonstrating antique or de minimis status; the latter will require documents confirming original ivory import date and date knife was made).
-No, you cannot sell it via interstate commerce if you cannot prove that it meets all the criteria as an antique or that it meets the "de minimis" exception.
-While the ivory sky may not be falling, it will be probably be more difficult to sell an ivory handled knife after 7/6/16, especially on public sale or auction websites. Don't be surprised if, as of 7/6/16, ebay (and/or others) either: (i) changes the rules for listing ivory items (mandating posting of photos of certificates, etc. which demonstrate antique qualification or de minimis exception compliance); or (ii) restricts or bans the sale of all ivory items outright.

Again, the foregoing is not intended to be legal advice, but an effort to clarify the terms and impact of the new rule."

FAQ is here: https://www.fws.gov/international/pd...final-rule.pdf