What you have there is a torque monster, fantastic long bar saw if you have the strength to carry and run it. I built a 051 for a friend a couple years ago, put a 25 inch bar on it and it felt a foot too short. It will cut three foot diameter wood all day. Their thirsty and do not skimp on oiling the bar. i'd say 700+ in value in excellent shape, my friend uses his every couple months to cut downed old growth pecan trees with neighbors. I modified his some so it cuts about 700rpm higher than stock...if memory serves it was approx 650 to build him that saw like to new condition including a nos piston.
Lots of nos parts out there, if you need a big saw i'd keep it.
