Just weighed the P-37D with mouthpiece in, about 1 lb. 12 oz (791 grams). It definitely feels lighter than the Suzuki M-37C. I think you were looking at shipping weight of melodica plus case, as Martin suggests, Julie.
You have to link the photo at another url — I do from my SmugMug photo site. I didn’t want to trash anyone’s melodica, but I know the Excalibur is a rip-off. Like some other “American” brands, it is made in China but presented, implicitly if not explicitly, as hand crafted in the U.S.