Fun idea if your villager’s house is already ruined: fill their ENTIRE inventory with the fossils so their home empties out, and then slowly replace each original piece of furniture in the house. There’s no guarantee it’ll be an exact replica, but you could try maybe? Im gonna test it out with someone i dont care too much for because ive ruined Poppy’s house with clothing :(
I always try to gift them furniture items that suit their home interior. For example: I have Deirdre and her house is mostly wood/woodenblock furniture with lots of browns. In the beginning she had only a sleeping bag, so I made her a wooden bed (didn't have the block diy one) and customized it with a donut pattern to make it more brown and it looks pretty good in her house.