10円や50円などほかの硬貨も、準備ができたものから作り始めます。
They will also start making other coins such as the 10 and 50 yen from the thing they were able to prepare.
I can't even guess at what 準備ができたものから is meant to mean in this sentence. What is もの referring to? The context doesn't help me at all.
Edit: Presumably it is simply "after they've made preparations", but I still don't understand the ものから part well.