Hi! I think that contacting the local Jane Austen Society or Regency Dance group might net you a tallish gentleman in the right era of garb. Also, with new fangled software, the image you have can be made to look hand painted enough to pass copyright. I have a friend, Walter Nelson, at lahacal.org who runs a fair amount of regency events. He might be able to point you to someone who could help. He's lovely, I've known him for twenty years and if you tell him I sent you, will probably be very helpful if he can.
Do you have the image above without type? I'd like to try messing with it if that would be okay.