What is the ruling on taking, repairing, and using an inoperable government device that was going to be destroyed, and do I now have to do something specific concerning it?

The Prophet, peace and blessings be upon him, warned against taking public funds unlawfully. The questioner must repent to Allah for what he has done by returning the compressor for public use, or returning its value, or spending its value on general Muslim interests if he fears it will be seized unjustly.