Z1000A1 front caliper

Hi, i have a caliper on my Z1000A1 that has a leaking bleed nipple, the fluid is coming out of the hole down the centre of the nipple, i have tried a new nipple , same issue, so it is not seating in the bottom of the caliper, tried cleaning down in the caliper but i have the same problem, im thinking the caliper is U/S, does anyone have a     caliper for sale in the UK.

You could try carefully cleaning the nipple seat by hand with a drill bit (10mm thread so an 8mm bit would clear) the nipple just needs a clean surface to seal against