"Gun-buster" refers to the gun in a circle, the intl symbol for no guns. By itself, it has no legal status in Texas. "No guns", "no weapons", "no firearms", etc. are all non-conforming signs, and have no force of law in Texas, including with knives. If you have an LTC, you can ignore all such signs that are not 30.06 or 30.07. This assumes the location is not already off limits by statute.
Any business or property owner who perceives that you are armed can ask you to leave, and that does have the force of law. You can be arrested for refusing to leave.
If you ignore non-conforming signs while open carrying, you have just invited them to ask you to leave. That is one reason that more people don't OC.
