What a cute idea this is! I couldn't follow the directions exactly because I went to 2 grocers and couldn't find cocktail rye or pumpernickel - finally asked at the 2nd store, and they only carry it for the holidays. But I used regular-sized bread and the other ingredients as directed, and they were great. I usually put thousand-island dressing on reubens, and I think I still prefer that, but others loved the mustard so it's nice to have that variation now! I plan to try the cute appetizer-sized ones when I can get the bread, and I'll post a pic once I do.