This scope is working correctly as far as I can tell but don't know much about it. For testing I connected the leads to a speaker (to be used as a type of microphone). Then played around with the various controls until I could see a waveform when I talked into the speaker.
That's the extent of testing.
Shows some wear but no apparent damage or issues. Has been cleaned up some (was covered in thick dust), can use some additional detailing.
Took a YouTube video while testing will share on request