About $20
Only Browning knows.
It means the 175th anniversary of Mexico's independence, or 1985.
I'm not totally sure but maybe it's a Quinseptumcentennial? This is a hard one. Let me know if this isn't right, please. The name that see most often is Septaquintaquinquecentennial. Good luck with the pronunciation.
It is called silver or silver year.
Why is the 16th anniversary called tungsten
In the US it's called a cotton anniversary, and in the UK it's called a paper anniversary.
US inventor Eli Whitney (1765-1825) was born on December 8, 1765. He died at age 59. The year 2015 marked the 250th anniversary of his birth. A postage stamp honoring Whitney was issued in 1940, the 175th anniversary of his birth.
A 100th year Anniversary is CAlled a Cenntenial .
It is called the "opal" anniversary in the USA.
Tungsten anniversary
A 100th wedding anniversary is called a "diamond" anniversary.