Contact the Smog Referee. Years ago when no one would test my pre-Tiger 1983 RV (too tall for the bays, too lightweight for the rollers they had outside), these guys really came through for me. I used the station at Southwestern College (Chula Vista); there is also a station at Miramar College.
"Assistance to Consumers when Smog Check Stations Refuse to Test Vehicles. Consumers may call the Referee Call Center to make an appointment if a station will not perform a Smog Check inspection on their vehicle. To reach the Referee Call Center, call (800) 622-7733.
Referee Program - Bureau of Automotive Repair - State of California
https://www.bar.ca.gov/Consumer/Referee/Referee_Centers.html"