The Comet is one that Airfix so very desperately needs to drag kicking and screaming into the 21st Century! Whirlybits does a cockpit set which can help to cure the worst bits of your model. The rest of it can be cured by a little bit of "Some modeling skills required".
Mike, you have some extra room above the nose wheel well to add more weight if necessary. I'd suggest that you tape it all together and test before closing up