Can I feasibly get a bonded title for this vehicle?

I posted here asking about how to register a vehicle that I was given in 2015, but due to some circumstances and miscommunication I was unable to do so. If you don't want to read that entire post and the subsequent replies, I'll summarize here;

The vehicle in question is a 1991 Jeep Grand Cherokee and does not currently run. It belonged to my father, but was legally registered to his California common law wife, my step-mother. Both passed away in 2015 and I was executor for my dad as his only bio child. I was given the vehicle by her son, my step brother, who was acting as executor for my step-mother and had no problems doing so until we ran into the issue with this vehicle, where we *both* discovered that he was not legally the executor, but his older sister was.

I moved to Minnesota before sorting all of this out (stupid, I know), in this vehicle that was registered to a deceased person in California and now technically belonged to a person that neither I nor my step-brother (who I also had limited contact with, and now NO contact with) can get ahold of. He was able to talk to her long enough to verbally verify that she does not want or care what happens to this vehicle (or any of my step-mother's things for that matter), but neither of us have talked to her since then and there is no way for me to get any kind of paperwork from her.

It has been sitting in my garage since 2015, and now I need to move it. I have the old title, I have the death certificate for both my step-mother and father, and I have notarized documents from my step-brother that were proven useless at the time. I would still like to register it, as it has sentimental value and would actually be useful to me at this point in time as I don't have any other vehicle. Someone on my linked post from before suggested attempting to get a bonded title, and that I might need legal aid to do so. I don't have a lot of money, and so would like to be sure that this is even a possibility before I look into it more thoroughly.

Thanks for any advice at all. :)