1964 NYWF .900 gold coin - info anyone?

Hi All,
A 1964/65 New York World's Fair Vatican gold coin, 32mm, .900, approx 1/2 ounce, deep Cameo Proof, designed by M.G.M. and manufactured by "NI", original Vatican velvet presentation box with Vatican key design. Anyone know anything beyond melt value? I have no pic nor have i seen it in hand. Coin has severe hairlines.
Thanks to all!
Eric
A 1964/65 New York World's Fair Vatican gold coin, 32mm, .900, approx 1/2 ounce, deep Cameo Proof, designed by M.G.M. and manufactured by "NI", original Vatican velvet presentation box with Vatican key design. Anyone know anything beyond melt value? I have no pic nor have i seen it in hand. Coin has severe hairlines.

Thanks to all!
Eric
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