James,
Assuming the brake calipers are the same as the 411 (I pretty sure they are), then they are Girling. Very similar if not the same as those used on the Aston Martin DB6 and Jensen Interceptor(? maybe not FF). There were other British cars that used them but they don't come to mind right now. I thought the XJ6 used Dunlop caliper? (the E-Types definitely did).
Don't replace them though, just get them rebuilt. When I got mine done I bought stainless steel replacement pistons (3 in each caliper) and seal kits from the a guy in the Aston Martin Owners Club in the UK, or at least he used to advertise in the AMOC Newsletter. It was 8-9 years ago but I will see if I can dig up the information. Whatever you do don't split the caliper in half unless you have the replacement seal that goes between the two halves of the caliper body. They used to be very difficult to source!
As for the door handles, I think they're also used in some MGs and I believe you used to be able to buy
chromed ones like this from the MGOC, again in the UK.
What other things need attention?
Kevin