[KC, MO] my grandpa financed a home for us, how do we protect ourselves when we are ready to sell

My grandfather financed a home during Covid when rates were low and “gave” it to my husband and I. Basically, we are making the mortgage payments directly to the lender and we are taking care of the house ourselves. My grandpa, my grandma, my husband, and I are all on the title of the house but, only my grandpa and grandma are on the mortgage.

We currently rent it out and have since bought a house in our own names. Though we lived there the first 3.5 years.

They are both getting up there in age, and my husband and I would like to sell it AFTER my grandpa AND grandma pass. (This is for emotional reasons. Selling it before they pass feels like an ungrateful move on my part because he put down a large down payment). We want to sell eventually because we have no desire to be landlords, and would eventually like to move to another state etc.

I am also afraid of random family members trying to claim ownership of the house. I can’t imagine anyone doing that because it has clearly been stated that it’s our house but you never know how people will react when he passes.

We discussed buying and financing the home in our own names, but with the interest rate at 3%, it doesn’t make sense.

We should also figure out how to make sure my kids are also beneficiaries too in the case that my husband and I pass.

What steps would you recommend my husband and I taking to make the selling process easier? Should we put the house in a trust in our names? What kind of attorney should we meet with?