Sims Disappearing when placing household

Yesterday, I merged 2 sims from the gallery into a new CAS household as well as created one brand new character. After making substantial edits to all three, I selected the checkmark to note I was finished and then proceeded to add them to a household (with one Sim currently present). I merged the households, and when the lot loaded, all four characters were present, but the only ones that showed as part of the household were the original sim on the lot, and the newly created Sim. Neither Sim that had been merged from the gallery showed up as selectable, and when they walked off the lot, they were never to be seen again. I think they were permanently deleted from the game. They are not found in manage households, and they did not show up in the relationship panel after having conversations with the active Sim. 
Please advise if there is a way to find these Sims again, they took some time to perfect and I'm sad that I've lost them.