Connecticut manufacturer Locomobile is best known for its artfully engineered, solidly constructed Model 48, which debuted in 1911 and remained in production for a remarkable 18 years, until the company’s demise.

Locomobile enjoyed great success following its debut, spawning a custom department that built bespoke cars for the wealthiest of wealthy, including William Wrigley Jr., William Carnegie, and several Vanderbilts.

Near the end of its life, Locomobile would introduce a new top-of-the-line model, the 90, boasting a modern L-head monobloc six-cylinder engine on a 138-inch-wheelbase platform slightly smaller than that of the 48.

It was a grand, imposing machine, one of the great inspirations of Locomobile’s final owner, William C.

Durant, founder of General Motors.

The Model 90 Sportif offered here, reportedly one of only two such cars in existence, is believed to have been formerly owned by Durant’s son, Cliff, a colorful racing driver known at the time as a frequent entrant a...