Humvees have a "body no." stamped on the outside A-pillar right below the windshield on the driver´s side. BUT that body no. does NOT match the VIN, although it is close most of the time. Won´t help you with the registration issue, but will help a bit with validating the 0619. 0619 would fit a 1985 model, however.
Overhere, we need to have the VIN additionally stamped into our frames when importing. After I bought my first Humvee, I cleaned the frame rails from dirty underbody protection grease, only to notice that the importer had stamped the VIN just into the underbody protection goo, NOT into the frame metal. After my cleaning, the VIN was gone ! Which practically places you in prison overhere, there´s nothing more holy that the stamped VIN.
Since I am a good, law-abiding citizen, I tried the official way to re-obtain the stamped VIN, but that turned out to be a buerocratese nightmare involving at least five agencies and ministries, who all were unwilling to help (and that even before they noticed that we were talking about a dangerous-looking, gas-guzzling former military vehicle...).
Luckily, my importer could help and had the Humvee re-stamped. But still quite a hassle....