1961 US "Flat Pack" Proof Set
1961 US "Flat Pack" Proof Set. Each of these 1961-dated coins were struck at the United States Mint in Philadelphia. 1961-P US Proof Set. Mint MarkP. The coins included in this set are Mint LocationPhiladelphia. Except for current year products, nearly all of our US Mint products have been previously owned.. Certification: : U.S. Mint: Circulated/Uncirculated: : Uncirculated , Strike Type: : Proof: Mint Location: : Philadelphia , Year: : 1961: Denomination: : 50C, 25C, 10C, 5C, 1C , Composition: : Silver, Clad: ISBN: : Does not apply , EAN: : Does not apply .