JC Wings has some exquisite moulds in its catalogue and has spent the past few years making some really nice new examples, to be used by itself and production partner Gemini Jets. Unfortunately, several 'recent' JC moulds also suffer from an issue that although easily resolvable has not been modified. It is an issue no other brand suffers from to the same extent - short undercarriage.
It may be the case that retro-airliners don't sell well but that's not going to stop me advocating for the history of aviation to be represented in 400 scale. Obviously when you're talking Comets it has to be Aeroclassics. The mould hasn't been used for over a decade but there are still some nice schemes that remain unmade, even Comet 4s that fit the mould's proportions. I wonder if we'll ever see them?