It's very hard to tell. It's not a first casting, from the photo the rivets look within the boundaries of many of my common models, unfortunately it's very difficult to see the rivet posts on these. There's slightly more wear on the baseplate lettering but that could have been caused by gentle play on a carpet, because the baseplate is so low. What is the paint finish like in the hand?
When we discussed this model on Lefora, I saw no reason to doubt its authenticity. Based on the above set of photographs, I see no reason to change my opinion.