You DO NOT NEED TO SHIP FROM AN FFL, just to an FFL. As a private party, just have him pick a local FFL that will receive a gun from a private party (completely legal), and then you ship the gun to that FFL. The Shootist in Murrieta will receive it, but that's maybe 30 miles from Riverside. Pendelton is a lot closer to San Marcos and San Diego and Oceanside than it is to Riverside. If you go north from Pendelton, you are in Orange County, and there should be a bunch of FFLs there who will receive it. Sites like GunBroker usually have a list of FFLs by zip code or city that can handle long distance transfers.
