China
People's Republic brass Winter & Summer Olympics 1 Yuan Four-piece Proof Sets 1980 Uncertified, KM-PS4 (KM29-32) and KM PS5 (KM19-22), KM-PS4 is in the original case, with COA, KM-PS5 has no case, or COA. All of the coins are fully brilliant, a few with small, minor spots.
Estimate: 300-400 USD