Some interesting thoughts on how to approach this, possibly, sensitive situation. My thought is that IF there is no jealously between the brothers, for some other reason(s), and, assuming, they all want to keep it in the family and keep it maintained, a fair way to do this is to have a "short straw", or high card draw, or something similar, that is equally fair to all 3 brothers. In the end, only one will own it, but the other 2 will know that it was done fairly, without favoritism or bias. I don't think there is a perfect solution that will make everyone happy, but it can be as fair as possible. I would also put something in writing that stated my wishes were for all of them to share it and to keep it in the family.
My father in law had a very rare early 60s Ford camper van. It was the family's only transportation for many years. They really had no money, so they went on family camping vacations in the van. They all have great memories of their times together. It's my understanding that he left the van to the oldest grandson. At one time, he may have expressed an interest in restoring the van, but, today, is not interested. The van just sits, unrestored. The people in the family who would like to see it restored and have the means to do so won't touch it because the title is in someone else's name. No one will discuss getting it transferred to someone else. It won't be sold and it won't be restored. A sad situation. I think there are people in the family that would rather see the van rust into dust than see it go to someone else in the family.