Hard to say if it is even possible to do, the older sets were designed using the available technology of the day, blue leds had not been developed yet, they almost all used the same sized 2 digit display that were available in the day they are almost impossible to get now even in red. They are smaller and do not have the decimal point on each digit so had less 2 pins and then there are 2 different types, common cathode and common anode. So to find out if it can be done would require getting the set up here and seeing what type it has then seeing if a larger one would even fit in the space, then getting one, there is nothing available in Australia that I have seen so it will have to be ordered from the states if it can be found online.
These are all variables on the cost, parts and freight.
The meter backlight should be straight forward but still not sure of the price of the high density blue led till I know what size it needs to be or how many.
I have not done cosmetic mods before so do not know (yet) where to scource the parts or their costs.
I would charge around $70.00 to do this which would involve many hours of net searching as well as hands on work.
