Fairbanks-Morse electric plant

I would like any information i.e. age, value, etc.on a Fairbanks-Morse electric plant that was being used as a backup generator on the farm I purchased 20 years ago. The identification plate is in good shape so most numbers were legible. Model W3S-250, serial # 76.304301, AC volts-115, K.V.A.-3, watts-3000, P.F.-1, amps-2.6, cycles-60, phase-1, DC volts-15, amps-10, watts-150, r.p.m.-1800, gen.no.-271338, gen.data-5039, Use 12 volt battery. It is green and measures approximately 34"Lx30"Hx15"W. Thank you

Brian, your FBM is a wolf in sheeps clothing. Actually an Onan, W2C series, probably mfd. late 30's to mid 40s. Very nice, good running plant. Fairly common, but not shown much because of size and weight. Many are military, also sold as, Onan and Wards Powerlite. Value? Two cents to 3 or 4 hundred bucks, depending on condition, location and weather.

I am trying to find a operating manual for a fairbanks genartor mod w3s-105 ser 106.312040 watts 2250 volts 115 r.p.m 1800