Strip Speedo failure, where to start?

I recently noticed a 'whering/spinning' noise that seemed to be coming from behind the dash at low speed /when changing from D2 to N (Series 1 SC Auto) and now, the strip speedo has now stopped working. Am I just best off checking both angle drives and the cable or should I go straight for the top angle unit?
The speedos themselves are pretty reliable so the angle drive would indeed be the first suspect. The one on the gearbox would be the first one to check, it's in the dirtiest environment.

All sorted, the right angle drive on the gearbox (Auto) was the culprit. I was able to get the 51 year old grommet in thr transmission tunnel out and back in without damaging it. Back on the road.