Keyboard clean completed. I removed all the keys, lined up all the springs on the desk (As simply throwing them in a box tends to screw them all together...), straightened up any bent springs, washed and left all the keys to stand in "Flash" cleaning solution, rinsed them, left them to dry in the airing cupboard overnight before re-assembling the keyboard earlier today. Looks a lot better (Though the cleaning has made the yellowed edges of some of the keys show up against all the spotless white keys...).
I've taken some photos of the operation which I might post one day.
Tip for removing keys: Use two identical screwdrivers, positioned in such a way as to prise each key up by placing a force on diagonally-opposite corners of each key in order to avoid any chance of breaking the keys off. Don’t try to pull the keys off with your fingers, as when the key comes loose your fingers tend to curl underneath the key and mangle the spring beneath. Oh, and don’t loose the springs –They can fly some distance.
Thanks,
Hodgkinson.