Neil with regard to roll cages it may be worth following the lead of the likes of the Dakar Trucks and vehicles used for desert raids. They have the cage integral to the cab. Keeping the the ability to tilt the cab and then have a roll bar mounted to the rear body which is seperate to the cab mounted cage. This gives you and front and rear cage that are independant. The front cage takes care of the crew safety and the rear roll bar should maintain the overall integrity. If you build a cage back to the chassis you will loose flex of end up with a cage and a cab that try to argue with each other won't you? Just my simple ramblings as i have looked at cages for wagons in general before and briefly looked at the mog however i have decided that i have far more urgent jobs than a cage. As good as it would look!!!