David,
welcome to the area and welcome to the Forum.
A good contact for Cobra insurances is Dan Hardiman. He is one of our fellow Cobra guys. A lot of us have their cars insurance with him.
His email is
dhardiman@prodigy.net or you can do a search of ClubCobra and find his phone number.
I think he should be able to help you, so there should be no reason to postpone your trip on Texas 289.
Best regards
Thomas