I don’t think, that 50# is realistic for a Hazel longbow with those dimensions.
This is my first bow - a Hazel ELB, 68” ntn, 30x32 mm at the handle. It took a lot of set (almost 3”), in spite of being toasted. And it has a draw weight of only 40# @ 30”. I’d say, Hazel is better suited for flat bows, but takes well to heat treatment.