I think I can take a look at Part 6 in a few hours if no one has done so by then.
Right now I'm just letting you know that I've found the actual recitation of the piece by who seems to be a pro in case you're interested. It will at least show you how the old kana should be pronounced if nothing else.
萩原朔太郎「夏帽子」朗読：岡崎ちか子: "朗読の森"をお散歩。。