I used to own a DS5000, it was sold as Agilent DSO3000 and the PCB was actually marked DSO3000.
Rigol was not allowed to sell 1Gsps color screen units outside of China as that was Agilent's market. So the sold 500Msps color units and 1Gsps monochrome units outside China, not to overlap the Agilent offering.
Interesting twist of events with Atten/Siglent.
Also, so funny and ironic that one Chinese company sues another over plagiarism..pot and kettle situation