Correct bolt for the alternator on 300tdi?

I've lost the bottom bolt that holds the alternator in place on my 300tdi 110 Defender. So the altnative is just swinging. I did measured the length and thought I needed a 150mm long bolt but did a google and saw someone suggesting that it's 130mm x M8. Does another know what length bolt I need to buy?

if it the long one, ERC8964, then that's M8 x 95mm

if it's the other long one with the flanged head, with the first 25mm threaded, BH108161L, superceded by FB108161, then FB108161L, and that's M8 x 80mm (http://www.brit-car.co.uk/product.php/85918/1079/bolt)

see page 162 on here: http://www.retroanaconda.com/landrover/parts_books/110/2_engine_25P_25D_25TD_p17-167.pdf

Thank you