As you found many insurance companies that might compliment a FAIR plan still refuse certain electrical setups. Knob-and-tube, fuse panels, active/aluminum branch wiring to name a few. Carriers don’t want the overall risk at all, even if the FAIR Plan is carrying the fire peril.
The California Department of Insurance actually publishes a list that will do DIC policies.
[https://www.insurance.ca.gov/01-consumers/105-type/5-residential/carriersDICpolicies.cfm](https://www.insurance.ca.gov/01-consumers/105-type/5-residential/carriersDICpolicies.cfm)
Just because they are on this list doesn't necessarily mean they are going to give you a policy though.
Have you talked with any neighbors?