I don't think manical is an extender of pragmatical, it's a separate adjective. He's a busybody, a little bit manic, and his solemn conceit is an air that he puts on, that's why it's ludicrous.
manical is just an -al form of manic, in the same way Dana uses pragmatical.
try it this way:
>was rather pragmatic, manic, and had a ludicrously solemn conceit

what say you?


formerly known as etaoin...