http://www.autosessive.com/products/3882/brake-shoe-setI don't know the Lucas number Sukram but this number might mean something - Delphi is Lockheed product and in the link the lower set on the LHD side are the 1999 +8 one's that I have just fitted.
I think you have given your car a heart transplant recently with an 1800 but if you were originally a 1600 the featured pads are the number you need.
These were less than half price including delivery compared to a common Morgan parts supplier and it is OEM specification and was a next day service as it turned out.
Heating of the fluid is a feature of thin brake linings and consequent turning to steam of any water in the system and reduced efficiency.