Hi and thanks for your replies

@ALBATROS1234: this is the only photo that I came up with also

The problem is that red and black look the same in vintage orthochromatic photos. I don't have any of the books mentioned, so my sources are the Osprey books (which I consider very reliable) and the Internet (of course). Wings palette have the black/white version (and only that) with the struts unpainted. Their source appears to be "Great Aircraft of the World", Len Cacutt, Marshall Cavendish Books Ltd. They have 3 different images, stating 1917 to January 1919. In fact these are the very specific profiles that made me want to build this. On the other hand, this started my confusion at the first place. They also have 3 or 4 other Camels from the 28th, but they don't have the same decoration, nor any other except for a huge capital letter on both sides behind the seat and a white square (which is not present at McEwen's machine). So I don't think the checkers have to do with the squadron. Next, about the struts, I haven't found any photo showing them unpainted, so maybe there was an inaccurate profile one day, and the artists that followed copied that. Were they replacable? I mean is it possible that the machine had painted struts once, but they were replaced later? I have no idea

@macsporran: Nice build you got there

, I hope mine turns out to be as good (which in fact is not very possible

)
The word "probably" means we don't actually know, right? What a huge opportunity to do ....... whatever

Thanks again to both !