I found a source that stated that in 1922, De La Vergne produced it's first true diesel engine, the model VG, designed for pipeline pumping stations.
Baldwin purchased De La Vergne and Cramp-Morris Industrials (once in the ship building industry) in 1931, that was a company that built hydraulic presses and stamping equipment. But Baldwin didn't have any application in their steam locomotive business, so they made De La Vergne part of a subsidiary company, the Baldwin-Southwark Company. The De La Vergne model VO was originally designed for stationary service. It wasn't until 1935 that Baldwin began applying the De La Vergne VO's for diesel locomotive purposes.