@IloveLondonforev@RandomBuzziness is right. If the lot you accidentally deleted is one of the original lots, you CAN get it back! Just follow the instructions in my previous post.
Whenever you start a NEW game, all of the original lots will be back. So, just start a NEW game, (which will bring the original lot back in that new game), then copy the lot up to your library. Your library remains between ALL games.
Then just re-load your previous game with the lot missing, and it'll be in your library. Just place it back again.