So I was wrong remembering 13k, where the border weigh is 11.500lb. Anything above that, or having UB- should go to the scales marked "no pickups" while all pickups should go to scales who don't have the sign.
How many 11.500 lb trucks have utility bodies on them?
Who told you about permanently attached camper to get RV sticker?
Over the years I registered 2 of F350 as RV.
The first one had camper shell, but that was year ago before CA turn "law officers" into "revenue seekers".
The 2nd I did about 4 years ago and it was originally C&C truck, where I added pickup bed and camper.