After its acquisition by Central Pacific, 173 was involved in a bad wreck, lying idle for two years before undergoing a sweeping reconstruction by the line's Sacramento Shops.

The Lilly Belle which resulted was widely copied by other "live steam" hobbyists, and became the basis for the future Disneyland theme park's miniature railroad's engine, the C. K. Holliday.

The locomotive was built in 1864 by Norris-Lancaster for the Western Pacific Railroad, which had it designated H in keeping with its alphabetic scheme and named it the Sonoma.

A train wreck involving CP 173 and 177 occurred at Alameda Junction on November 14, 1869, and both engines were brought to the railroad's extensive shops in Sacramento two years later.

Though extensive damage was sustained from the wreck, Stevens found many of the engine's parts to be reusable, and had decided to use the 173 as a test bed for the railroad's entry into the locomotive manufacturing business.

The rebuilt 173, finished in November 1872, was well-received by the railroad, and soon the shops produced twelve engines based on its design.

*Named Wilmington, number unknown, later became SP#33 after the Southern Pacific Merger, #1311 in 1891 and scrapped in 1900.

Drawings for Disney's model were likewise provided by Joslyn, with 173's proportions scaled down to 1.5 inches to one foot.