I'd place that fish between 45-55lbs, likely around 50lbs.  My roomate had one that was 50lbs 1 oz this spring that was very similar in size.  Yes the world record was 53", but that thing had a HUGE belly and the girth of that whole fish was huge.  Your fish is a great one, I know of many guys who'd love to land one that big.  My largest so far is 42lbs and it was smaller then that fish, but I have tons of years of fishing left so hopefully I can best that 50lb mark in my lifetime.