Welcome to Purrs, although no doubt we would all wish you had found us in happier circumstances than your beloved boy having gone missing. He's very handsome.
I do hope that you get him back quickly, and safe and sound. There's a lot of useful information on the forum in connection with trying to locate missing cats, just in case you want to check and make sure you have all of your options covered.
So many of us know directly what you're going through, and how devastating it is when they're missing. Please accept a heartfelt wish from us all that Larry Grills comes back to you soon.