Rear shock - top mount broken - safe to drive?

It is unsafe to drive that far, slowly and carefully to a local garage will probably be OK

I wouldn't.

I'd slowly drive it home or to a garage to be fixed, but wouldn't go more than maybe 5 miles ...

As you know the suspension to be defective it's possible that if you're in an accident the Police would take a dim view of it, to say nothing of your insco ...

I know someone who did a track day at Castle Combe in an MX5 with knackered top mounts - he didn't die.

I've finished an enduro on a Honda XR twin shock, with only one shock, though this was the bottom mount fecked .. but I wouldn't drive on the road with it .. I didn't die either, but neither did I win. I suspect the not winning had little to do with a fecked shock mount. ;)

I've got to drive 200 miles to customer and not sure if I can get it fixed beforehand.

lose and the shock is rattling around. When driving, it gets really rattly.

Has the top rubber bush worn out?? not the top of the shock broken. get either a new shock or replacement rubber bush.