Excellent discussion gentlemen, thank you for all the responses and tips.
My Elan sat for 25 years untouched and the as a result the piatons were a complete pain to get out, took several hours and I to learn some new four letter words in the process as well.
Ultimately I ended up replacing them with stainless steel units, my hunch/hope is that these will be OK as the brake fluid that came out when I disassembled everything was surprisingly clean so I don’t think the car was sitting quite so long.
I will, carefully, get some high pressure air on these later today to see what I am dealing with.