The P-37D was available starting in 1988, Kevin, and the P-32D in 1984 (I know this from a replacement parts list), though I’m not sure about availability in America, but some Yamaha Pianicas were available here earlier. Does your generic say “Pianica” on it? and did it identify its place of origin: Japan, Indonesia, or China? There are several companies that have the right to use the “pianica” label, including the original manufacturer, Tokai Gakki, which currently has a couple of models on the market. They and some others with the rights to use the name have the duckbill kind of mouthpiece like the Yamahas. The cost may not be indicative of much, since some vendors have passed off cheap Chinese melodicas as “handmade” and whatnot or given the impression that they are Yamahas or are made in America.