I like this idea.
I think the real solution though is there should just be 1 GC Seal "currency" instead of 3 different currencies. They should come in different denominations (10's, 100's, 1000's = copper, silver, gold) with rewards based on company allegiance.
Then everyone could purchase items/gears from any GC Office but non-members have to "pay" a higher price in seals.
Problem solved (easily) imho.