The 1953 Series 1 now has a 5 gallon fuel cell tucked up high under the seat in place of the original tank, but the biggest step forward is a custom-fabricated roll bar. It's tied into the chassis via the outriggers. It incorporates a custom spare tire mount too, which solved another problem since the fire tender didn't have the stock mount behind the seat bulkhead.
A guy in West Chester who works on Austin Healeys and other British cars did the fabrication work. He did a great job at what seemed like a very reasonable rate. He also did work on my non-Rover off-roader that worked out well.
Jeremy