Arthur Wallace provides the following information in his book, ,
Mason Steam Locomotives.
American Fork RR No 1. c/n 461, 0-4-4T delivered July 1, 1872.
weight on drivers 24,000 pounds
10 x 15 cylinders 33 inch drivers
overall llength 29 feet 6 inches, wheelbase 20 feet
Wallace reports the locomotive was the first 36 inch gauge locomotive constructed by the Mason works.
A service report says the locomotive handled 40 tons on American Fork's ruling 5.6 % grade at 12 miles an hour. The locomotive proved to be too light after a month of service and was not used by the railroad thereafter.
Hope this helps