I do not think they would grant a restraining order. The only way this would be likely is if your sibling was actively trying to sell the assets. Otherwise, there are monetary damages available, so the court would probably not give you injunctive relief. You might be able to get an estate open and have an executor or administrator appointed, pretty quickly.
If your sibling had the deed set up through an attorney, you will need compelling evidence to set it aside. I would get all of your father's medical records that you can get a hold of, right away. Your attorney will need to see them. And you WILL need a very good probate litigation attorney to assist you with this.
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You didn't mention in your fact pattern how your sibling was able to accomplish executing a quit claim deed or transferring title to the vehicles. Did your sibling have a power of attorney? When was it executed? Did your father have the capacity to execute any such documents? These are some of the issues that immediately come to mind. You need to take all of our documentation to a qualified probate attorney with litigation experience in your area. After a thorough and careful review, the attorney should be able to provide you with guidance on how to proceed.
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