On the HMMWV in TEXAS it makes a big deference if the GVWR is over 10K, under 10K even with the "off road only" stamp license plates are unrestricted.
Over 10K looks like a problem, so advise stay away from the "Heavy Variant"
Here is the pertinent part of the law..
""DETAILS
HB 1755 adds Transportation Code, Section 502.141, which makes certain former military
vehicles with ownership evidence that indicates off-highway use eligible for passenger or truck
registration. Effective September 1, 2019, a High Mobility Multipurpose Wheeled Vehicle
(HMMWV), commonly referred to as a HUMVEE, with a gross vehicle weight less than 10,000
lbs. and ownership evidence that indicates off-highway use is eligible for passenger or truck
registration.
Qualifying HMMWVs can receive any registration type the vehicle or owner qualifies for and all
applicable requirements for the registration type chosen will apply. HMMWVs with ownership
evidence that indicates off-highway use with a gross vehicle weight of 10,000 lbs. or more are
ineligible for regular registration and may only be issued Antique vehicle registration. A former
military vehicle with ownership evidence that indicates off-highway use, other than a qualifying
HMMWV, may only be issued Antique vehicle registration. HB 1755 does not impact the
registration of former military vehicles with ownership evidence that indicates off-highway use.""
The GVWR is clearly listed on the title documents provided by Richie Bros.