I did that years ago, pulled out non working clock & replaced it with a Smiths brand clock. looked like shit in G.T.S. dash compared to original one. Spend the money & get it fixed is my advice. If its buggered get onto Oz, im sure he'd have some for sale. If you cant find one, im pretty sure I could organise one around the place, is it white or yellow needle?

cheers
Max