Where do you get this bolt

Can't find this bolt anywhere, the one that holds the speedo cable into the transmission housing on 5 speed Golf Gti. Parts diagram says its an M7 x 1.25 pitch x 13mm long. Really unusual bolt so finding it hard to get one. can anyone help please?

is it not the same size that holds on the flywheel cover to the gearbox underneath?

I'm not sure, it's got an unusual pitch of 1.25 where most m7 machine bolts are 1.00

could try VW, N 0901733 - fillister head bolt (combi.) -
M7X1,25X13Z3

worst case scrappy, look at mk2 or even mk3 golfs. all the 1.8-2.0 mk3 8vs use the same box so the bolts from them can be pinched