Dear Robert, I'm sorry to read that you did not feel well, unfortunately my house is very old, I decided to preserve it because it is my favorite place in the world and I would not change anything, and many guests who came before you told me that I'm doing well, even if I had to make several changes to make feel good who, like you, would have been hosted.
For the future, since the problem of your wife's allergy is so overwhelming (you told: "I probably wouldn't have even noticed this if she had not been there"), I suggest you to choose houses that already seem more new and less "dark and stuffy" from the photos. It will surely be an advantage for your next trips and also for your next hosts (since it is useless to write that the house is ancient and Spartan in the announcement, because it seems that nobody reads it! ... read all the price, that yes, it's low and it's worth it!), that they will not have to be subjected to negative feedback because the guests do not read the ads well. ;)
I also add that maybe my friend (who was doing me a favor, since I had something unpleasant and I could not be present), maybe made you wait a bit 'and for this I took a star less at check in and at communication.
While your 5 stars in communication are not lacking even if, both when I asked you information on the check in, and when I asked you where you had left the keys at check out, you made me wait more than 8 hours for an answer.
Before writing the feedbacks, take a conscience exam.