Speedo arm snapper, speedo stopped working(see photo)...how can it nb fixed?

I need to remove plastic front superglue arm back on and refit speedo cable. I live surrey hampshire border and need an enthusiast to help me fix it before the MOT

Not really.  it is rather brittle plastic, but you can surely try.  When you pry it off the center needle do it from 2 sides of the needle.  I broke one once… so I use a pair of curved hemostats that opened neatly straddle the center pin. And use a piece of paper on the face plate under the pry's so you don't scratch the face plate.

Probably easier to source a new cluster than a needle.