Be wary of any manufactured home built before June 15, 1976 as they are "PRE HUD" homes and will be very difficult if not impossible to finance. Additionally many if not most PRE HUD homes were built using caustic and carcinogenic chemicals i.e. formaldehyde and asbestos.
But before you purchase any manufactured home you should have the home inspected by an experienced manufactured home inspector and not just any home inspector.Make sure the home is level and that the pier and pad assemblies are in good shape.
Be sure the vapor barrier and insulation are in tact and not ripped, torn or lying on the ground. Have the inspector look for drainage issues i.e. standing water, soil erosion, expansive (clay soil), rusted and deteriorating piers and dry rotted or decomposing wood pads supporting the piers.
Most importantly make sure the home has an approved set of Earthquake Resistant Bracing installed under it as much of California is in a Zone 4 seismic area: