I ran into the same problem as many other people in trying to find the 12mm fitting for a 1" master cylinder. After scouring the internet for weeks it seems my grandfather (who races British Vintage touring cars.) turned me on to a race shop near his home town, and voila here are the fittings. So what follows is there website. The -3an part number is 3265-45
www.pegasusautoracing.com/advcat.asp?CategoryID=BRAKEADAPT
www.pegasusautoracing.com/advcat.asp?CategoryID=BRAKEADAPT