Re: Fritz and Fredersdorf's respective figures - actually your original impression was correct, going by what we know. Fritz didn't become thin until the 7 Years war, where he really had a major weight loss. (He remained thin thereafter.) Fredersdorf, otoh, if you compare the two portraits we have, the one from my icon to this one from later in his life seems to have lost some weight, if anything, though nothing as dramatic as Fritz pre 7 Years War to Fritz post 7 Years War. Meaning: in early 1756, when these scenes take place, their weights are wrong for the characters. But yes, the Fritz actor does look very much like him anyway.

I'm glad my evil intentions in making these screenshots worked, and made you laugh. :)