"This castle is the undertaking of one man's own mussel and sweat who started it in 1969"
I think that muscle is what you were looking for here. Your work on this page has been excellent, but there are a few choppy or confusing sentences spread throughout, and it could probably use a little bit more proofreading. If you'd like, I could email you some more specific sentences, but I'm not going to put in the time right now.