The Roseville freezer situation
Roseville's postwar ramblers around Owasso, Lake McCarrons, and Josephine Heights nearly all have a second freezer in the basement — chest units from the 1990s and 2000s that are still running, and uprights in utility rooms and attached garages. Those machines are simple and long-lived, and when they stop holding zero it is almost always a gasket, a thermostat, or a condenser choked with basement dust rather than anything exotic.
The lid gasket is the one people overlook. Twenty years of closing flattens the foam and hardens the rubber, and the lid no longer seals across its whole length. Warm room air leaks in continuously, frost builds on the food, and the compressor runs far longer than it should while still losing ground. A gasket replacement is the highest-value repair on the list here.
In the kitchen unit, a freezer that is cold but not freezing is a partial airflow problem: frost slowly accumulating on the evaporator from a weak defrost circuit, or an evaporator fan turning below spec. Both reduce the volume of cold air without stopping it, which is exactly why the compartment lands in that 15–25°F band instead of failing outright.