Some trust being gained?

For about the last six months or so I have been feeding the feral cat colony that lives in our apt. complex. the particular group that I feed consists of about eight to ten cats. There is one mother and I assume by the looks of the others that they are her offspring. I have never been able to get close to any of them until tonight. The mother and three of the younger cats actually came within a few feet of me as I was sitting the food and water down. Mama Cat as I call her almost let me pet her for the first time but at the last minute pulled back. But just the fact that she got that close to me was a nice feeling. It felt as though she was finally starting to trust me. There is one large male I call "Big Blackie" He looks to be very old and walks as if he has really bad arthritis or something. He has always been really friendly and enjoys tummy rubs and being petted. But lately he doesn't seem to want to be touched at all. I really think that he may be getting ready to die. I sure hope that I am the one to find him so that I can properly care for his body. I hate to think of him ending up in a dumpster or even worse just lying there to decompose.