In「命火眩暈」by 杏ノ助, there are the following lines.
頽るる松、 甲羅なき亀 御簾を上げれど けふも宵
The other text is perfectly imitating a Sengoku-period Late Middle Japanese with occasional classical. However, this particular form is unexplicable to me. It look like a modern-language use. I can only understand it as if there was a 四段 verb あげる, which, according to the dictionary, never was; for an actual あぐ, which is 下二, the correct form would be あぐれど. What is happening, a carelessness of author or some unclear intent?