I find it amusing that two people are arguing about the "authenticity" of whether or not a repainted inexpensive item was repainted by one person or another. There is no added value, IMHO, to having a Welz repaint job over a repaint by anyone else. It's not as though the Welz provenance adds any great value to such a mundane item.
True, Elliot's work was better than 1st class. His painting and detailing were museum quality, if there is such a category in old non-scale GG1 shells. The one you pictured is simply not one of his. Let the seller be angry. Walk away. A better one will come your way eventually.