Common, he can literally teleport no? Just change your appearance and sell the gold piecemeal all over.
Either way, this feels like such a roundabout way to do this. This is magic. There literally is no legal precedent that has it in the law that it is illegal to manifest income via magic.
So his excuse about "not wanting to do anything illegal" is kind of pushing it.
Also, each of those works could likely go for thousands of dollars if they are made from genuine gold, silver and pearls/crystals... and he just hands them out for free, I dunno, I feel like that would stand out more the moment one of them goes to a jeweler to ask for its worth.
Hell, in fact, why isn't he just selling them to jewelers? They are more than willing to purchase those things so long as you don't seem shady.