People like to call these "experimental" for some strange reason.
When something was experimental, they noted it. The 1905 meat can was experimental.
The M-1906 cup wasn't.
The Cup, M-1906, (Aluminum), Non-Experimental.
How many did they make? That is hard to determine. Every year they decided to get creative on how much they made. Creative in how they'd list it. Cups, aluminum. Cups, aluminum, with slotted handles. Cups. Never the same nomenclature. Call it 45,000.