One of the problems with upgrading older parks in California is Southern California Edison. They want to charge the owner for the entire upgrade fee for their Transformers, wire, poles etc. When I owned a Park in Mojave, California I would get monthly updates regarding the Park industry. SCE was taking the attitude that to allow Parks to upgrade their Services to accomodate 50 amp power, the owners would have to pay for all of the infrastructure because the pay back was too little and too long in charging them a higher monthly rate. Anyway, I do not remember the final outcome of all this, but most small RV Parks would be hard pressed to re-design their electrical systems unless they could justify the cost over 3-5 years. My Park, Sierra Trails, had a combination of 30's and 50's with some on their own SCE meters because it had once been primarily a Trailer Park.