what other currencies were used in the past before gil was adopted?

[Kaiser-Ace]

I feel like past currencies would make for a really cool rare drop (like, ULTRA RARE), and be exchangeable for unique items or much larger sums of gil, kinda like the way if you find a really old coin now it could be worth substantially more than it's printed value. Not only would this be plain cool, but it would make for a nice (albeit very rare) bonus for people who run dungeons and raids regularly. Kinda like the syrcus shard drop in ST. It was super rare, but was a pretty hefty reward if you ever saw it.

Make it a random drop too instead of a chest item. Like the way the Inferno Horns and stuff worked pre 3.0.