A Bank Biulding

I was thinking of something like Red Ketchup choo choo mechanic to create a bank building.

The building could convert coins, silver pfenning, gold coins, silver bars, gold bars into 24k Gold Bars diamonds that could be used for trading (trade posts, trains )  and they will use much less space than the input stuff.

The bank could also have some inventory space to be used to store precious items.