This is the second to last version of the 0-4-0 steam switcher Lionel introduced in 1939 as the 1662.
The 1615 has a plastic tender and magnetic couplers. The 1625 replaced this for 1958 only and is the same except for a dummy coupler on the front.
These switchers don’t run very well because they lose current in 022 switches. The earlier 1656 and 1665 and the prewar switchers have pickups in the tenders and go through switches at slow speeds much better.
Many Lionel 1615 switchers are found with the marker lights broken off. replacements are available and aren’t that hard to install.