There isn't anything that you can call the 'correct' tonal value, it's all very subjective, so as long as it looks right and you're happy with it, then I'd say that's fine. Everyone will have their own preferred tone if they were to do their mono conversion so I wouldn't worry.
When I do mono conversions, several different settings can all look fine and are just that - different.
For example, you can push contrast harder in mono, and the sky here is a case in point. It can be darkened and made more contrasty. his would look good, but if it's not the 'mood' you want, then leave it as it is, as there's plenty of detail and texture there already.
there's good shapes and tones in the image which makes mono work well, and I prefer this over the colour one.