Welcome to the forum! Your Monark is from 1958 or later, after Huffy bought the co. It's basically a renamed Huffy. The serial is odd, it does have the typical Huffy H as the 2nd digit, but most common is something like "8H80000" which would be 1958. It's definitely not a 56, and they pretty much retired the Monark name by about 1964. Definitely early 60s vicinity though. -Adam