Abstract: An improved version of a solenoid-releasable Baldwin® mortise lockset having thumb-lever actuators is provided. Components from a thumb-lever-actuated mortise lockset are combined with those of a knob-actuated mortise lock from the same manufacturer. The sheet metal of the rocking bolt-locking plate of the knob-actuated lockset and of the exterior thumb-lever actuator bracket from the other lockset are thinned in certain regions. In addition, a new vertical-to-horizontal motion converter arm has been designed and installed in the improved lockset. A rounded upper portion of the new converter arm operates on a bottom edge of the bolt-locking plate, causing it to pivot and release the latch bolt. The new converter arm retracts the latch bolt by operating on a projection on the front side, rather than on the back side thereof.