But no one tried to show her her mistake; and when she had ended her song Joe was very much moved. He said that there was no time like the long ago and no music for him like poor old Balfe, whatever other people might say; and his eyes filled up so much with tears that he could not find what he was looking for and in the end he had to ask his wife to tell him where the corkscrew was.
My initial impression of the ending's ambiguity is that Joe has feelings for Maria as he was so touched by her singing. However, I feel more confident in saying that perhaps Joe also lives a rather simple and ignorant life. Joe's difficulty in dealing with the song (for whatever reason) is quickly pushed aside by distracting himself with the location of the corkscrew.