Are we the AH if we take back a motorcycle from my uncle?

My father works abroad. Originally, my mom, my sister, and I lived in the city while my dad’s hometown was in the province.

About 5 years ago, my dad bought a motorcycle in the province. The main purpose was to help my grandma with her funds. Since we weren't physically there at the time, the motorcycle was registered under my uncle's name instead of ours. The agreement was that my uncle could use it as a motorcycle taxi to earn a living, as long as he gave a portion of his earnings to my Lola regularly.

Fast forward to now: we just moved to the province to live here permanently. We recently found out that my uncle has barely been giving my grandma any money for her funds over the last 5 years.

Because of this, we want to take the motorcycle back from him. The big issue is that the papers are legally in his name, so I don't know if we even have a leg to stand on to fight this.

On top of that, they are heavily guilt-tripping us using the typical "family" cards. They are saying things like we don't trust them, or asking, "Why are you treating us like strangers?"

I don't know where to go from here. Any advice on the legal or family side of this?