Hi, it's never easy to lose a beloved pet, do you ever really get over it? I lost my previous 2 cats within a year of each other and that was 15 years ago and I still get upset about them. As for Alfie, well he is clearly at a loss as to where his friend is, my two cats were like brothers (they weren't related and there was a 2 year age difference) and when the younger one died first the other sat on his grave and on the fence above it and you could tell that he knew that's where his friend was laid to rest, he was clearly grieving for him and continued to do this for a long time. You know your cat best and whether in time he would accept another cat in to his home is something you can decide if and when the time is right. I am so sorry for your loss it always upsets me when I read of someone losing their pet and you will be in my thoughts, give Alfie a big cuddle for me.