I need to know the silver content of this coin, not in catalog

  In the

Series: History of America

there are only these three on the site

https://www.ngccoin.com/price-guide/world/liberia-20-dollars-km-1378-2002-cuid-1944641-duid-1945458 

https://www.ngccoin.com/price-guide/world/liberia-20-dollars-km-1379-2002-cuid-1944642-duid-1945459 

https://www.ngccoin.com/price-guide/world/liberia-20-dollars-km-1380-2002-cuid-1944643-duid-1945460 

but all those have

Fineness: 0.9990

if that helps. 

Thank you. I also have these 3 coins with the certification of authenticity.  I was hoping someone would have firm evidence that the ones pictured are .999 Ag.  It may be acceptable to assume that they are .999 Ag because all of the “History of America” coins that I have are .999 Ag certified.  However, it seems some may be .925 Ag, which causes some concern when listing them. 

Thank you. 

Does anyone know what a .925 AU coin of the same size would weigh?  Am I still looking at 20 g?

You mean silver (Ag) not gold (Au).  No, just a minor thickness difference could make them the same or different.  That won't tell you a thing between .925 and .999 silver.

Thank you, yes Silver Ag. 

I am hoping to find someone that has collected Liberian $20 Ag coins that has a duplicate coin in their collection that still has the certification certificate.

 A coin $20 from Liberia 2001 has this certificate 

https://www.ebay.com/itm/236565440536 

 which yes is a different year and coin 

Thank you, would you suspect all of the “History of America” series are .999 silver?  So far, all the ones I have, that have been certified, are .999 Ag.

 I would suspect that, yes.