I can't say, obviously, without playing the instrument, but if it were me, I'd sell it and, if desired, basically swap it for as much Yamaha acoustic as you can get.
When I was a teenager and lived with my folks, we had a Kimball (I don't remember the year, but it was pretty old) supposedly from a deceased grand-aunt who was some kind of piano teacher out in the sticks.
I don't remember the exact length, but you could call it a baby grand size.
Very loud. The voicing of the hammers was terrible, at least to my tastes, the sustain and una corda pedal mechanisms were not good. I don't know if the pegs were all messed up from age, but it wouldn't hold a tuning.
The best piano tech in town, she couldn't even do anything with it, and basically said forget about it, let me only play and work on the old honky-tonk upright on the other side of the room. She could tune it, of course, but that was her opinion as well.
I guess it was a good piece of furniture, and I've visited back there a year or two ago and did a little session on it, just me alone doing some jazz stuff, and it still had those qualities, but I could get a bit of music out of it. Probably just from years of experience playing on bad pianos.
The action was heavy, but I kind of like a heavier action, just for the tactile feedback. Not sluggish, but heavy.
So, the action was OK, and it made for good furniture, I guess, is my summary. And I restate, it was appallingly loud, even for a pretty good-sized room, but you're going to get that anyway.
So, I don't know for your case, but that's what I know about Kimball pianos.