Thanx for commenting, colleagues!
Carl, the thing is that the engine is still quite visible on Nieuport 17. I wouldn't go into scrathcbuilding and detailing other parts of the plane, lefting the engine untouched

I try to to build the kit that it would stand out from others I've built. So I really need resin engine for this one (Eduard's LeRhone looks wrong and needs modification to sit right (I mean that exhaust pipes face the firewall, not the whole in the cowling).
Stephen, thanx for advice! Frankly speaking, I haven't noticed those ones! Just have checked my references and some photos really show those cut outs on the cowling.