You’re right but in America we use the agricultural example as it was a big shift in our market thinking. I didn’t know about metal futures but I did know about Dutch and how they created futures and securities. I believe the Dutch East India Co to be ahead of its time and because of world politics (and war) it didn’t survive and was nationalized. A lot of papers about our CME here in the states talks about it. I’m not an expert but I do know we use the agri example because it’s one most would be familiar with since it was a somewhat recent addition.
The Dutch (and after the idea had crossed the Channel, the English) were trading debt from the invention of exchanges.
The CME might have started with FX futures in 1971, but they're hardly the first non-agricultural use.