Casey,
Your Grandfather's Heisler was built 04/1911 as construction number 1225 with 10X10 cylinders and a tractive effort of 8000 lbs. At 18 tons she is the smallest Heisler left.
She was built for the Richardson Lumber Co. then was sold to the Lake County lumber & Box Co., the W.W. Prather Lumber Co. and finally to the American Box Co.
In the mid 1950's she was discovered abandoned on an old logging road near Clear Lake. Jim and Richard Holmes bought the engine and had her moved to Billy Jones' ranch where they ,the late Charley Ward and the late Niel Vodden rebuilt her and fired her up( they called her the Elk). Your grandfather bought her from the Holmes Brothers in 1959 as Billy had no 36 inch gauge track.
I hope this is what you were looking for.
Tom