Jan, we grieve with you. The loss at a time like this provides the contrast to appreciate our blessings. I'm sure your Simba and my beloved Kiki are both up there peering down through the overcast keeping an eye on us blundering about without proper feline supervision! I'm sure Kiki feels "the new gal" isn't up to the job. Hang tough, Shipmate!
Sad news, my condolences. It´s a very good thing that exists people like you that have a very kind heart to care their pets and bring them the best life that they deserve. By sure that Simba had a very happy life with his human brother. RIP in the cats heaven.
Jan, I just noticed this and you have my heartfelt sympathies and condolences. They are more than pets as they are really family members. The grief is just as painful and the loss is just as deep as what we feel for our human companions. In time I hope you find another one to give as much love to as you did to Simba.