The space-bar was sticking because I spilt something on it. And I thought it was time it was cleaned, so I tried to figure out how to get he keys off.
I found that levering the top half and then sliding the key up worked and as I was encouraged by how simple it was I took all the keys off and cleaned underneath them.
Then putting them baci I came across a half-dozen or so which wouldn't come back up again (space bar:- T,A,S,D,F,G,H & K).
I Think the holes in he keys underneath where the hinge slots in is rough or bent on those keys and so they don't slide as it should (IYSWIM).
... With the exception of the T key, which is sitting on the edge of the keyboard because I managed to compleely stuff the hinge for it.
My plan of action is to carefully remove the sticking keys and rub them with a very fine file or a modelling knife, and I'll put a small spring under the T key and basically glue it in place.
Tricky! But I'll have to do something! I'll go over this post now and try to fix the mess - and it IS a mess!
* But the underneath of the keys is beautifully clean! I could eat my dinner off it (Something I ought to avoid doing along with not spilling drinks on it any more). - Electrically it is serviceable