My cat, Marty McFly, went missing on Friday 9/17

Hi, My cat mysteriously disappeared on Friday (September 17th). I'm looking for any help I can get. We live in Lawndale/El Camino Village near the crossroads of Manhattan Beach and Prairie Avenue. Marty is chipped and the chip maker has my updated information and has not been notified of Marty's whereabouts. I've checked in with local animal control for Carson and Lawndale, but their logs in my area don't show this type of cat either. Marty is Siberian, weighs about 13.5 lbs, and he's about 6.8 years old. He's a lover and a fighter, so please notify me rather than approach him. If he's scared, he may scratch or bite. Since Friday, we've had a couple "tips" but they haven't amounted to much. Thus, I'm trying to reach out to the larger community for help. The first tip (Sunday evening 9/19) was a person on next door informing me that they saw a deceased cat on Manhattan Beach Blvd, near my road. He mentioned that his neighbor may have moved it or called animal control. I'm still trying to sort through this tip as if Marty was picked up, his chip would have been ran, and he would have been in Animal Controls logs. Since neither of these seemed to happen, I don't believe what he saw was my cat. And just now, this person confirmed it was a different cat. Whew! The second tip (Monday afternoon 9/20) was a person that saw a flyer we put out. She said that she saw (late the night before) and fed a cat that met Marty's description. She said she always bike rides though the campus and feeds all of the cats she can. She also owns three of her own. She noticed that one cat was clearly domestic and not like the others. She met up with us on Monday to show us where she saw him, but it seems he went on his way. We'v