I don't think that's a very good representation of the aircraft in it's WW2 state. It's a frankenstein made from spare parts after the fact.
If you're talking about the small blue circle on the starboard side (and the smaller red one next to it) they are power connectors so that the aircraft can have power while on the ground, and to recharge batteries and whatnot. Although, these seem to have been less visibly marked in later planes and on a G14 they wouldn't show up like that at all.
As for the position of the fill point, this moved from plane to plane, it would be one place on a D, another on an E-4, another on an F-4, etc. It is possible they just took any old tail/fuselage structure and tacked it onto this plane, or even used another plane fuselage to recreate the G14, and that could mean it's not really a G14.
In short: The skin has the position correct, from what I've seen in other places.