I clicked before I looked and I suspect that I only pre-ordered the standard version...there's no option to upgrade to gold either...yet. I'll wait and see before I refund and buy the gold version.
Edit: I take that back, checked my purchase history and I did indeed order the gold edition![]()
Maybe you can email the developer Warhorse Studios or Steam about how to upgrade. You could also buy the expansions later, but that will cost more.