One of the sales tactics used by the Booker T. Washington Birth Place Memorial and George Washington Carver National Monument Foundation (aka Sidney Phillips) was to send out commemorative half dollars on approval with the hope that the recipient would keep the coin and send in the requested amount to purchase it.
Years ago, I was fortunate enough to come across one of the envelopes used for such "Approval" mailings. It was for a George Washington Carver - Booker T. Washington Half Dollar.
Envelope Used for "Approval" Mailing of GWC-BTW Half Dollars
From the wording printed on the envelope, it appears that an Order Blank was sent with the coin and was to be returned with either the coin (if not interested) or with payment (if purchasing the coin). The Peoples National Bank of Rocky Mount (Virginia) was listed as the party that would accept either.
The Peoples National Bank in Rocky Mount, VA was the Birthplace Memorial's bank, and it was one of the locations that collectors could send orders for processing - it was referenced as such in press releases sent out by Phillips. The Birthplace Memorial and the George Washington Carver National Monument in Diamond, Missouri (GWC's birthplace) were also listed in publicity notices as places to which orders could be sent.
The envelope is undated, and as I do not have the original outer envelope that was used to mail the piece, I can't state definitively the year it was used. However, I believed an educated guess of 1952 would be reasonable. More than ~2.022 million GWC-BTW half dollars were struck in 1952 - dwarfing production in the series' other years. As Philadelphia accounted for 2.006 million of the 1952 coins - again dwarfing all other facilities - I would also guess that the "For Your Inspection..." initiative used Philadelphia Mint coins vs. Branch Mint pieces (but I can't be 100% sure).
The $2 price point listed on the envelope was a good deal, as single Philadelphia Mint coins were being advertised for $3.00 by dealer-distributors at the time.
1951-54 George Washington Carver - Booker T Washington Half Dollar

For other of my posts about commemorative coins and medals, including others about the BTW and GWC-BTW half dollars, see:
Commems Collection.