Brake M/C US 78 400A

Hi Gents,
The Brake M/C on my 78 400A is US and need to replace, The one on mine looks different to the supposed replacement as mine has the hexagonal screw in part in the end, has anyone used the new one on a pre injection 400 with success?

Mine but for LHD car
http://www.mediafire.com/file/d7wlz38fhzjpli0/ferrari-400i.jpg/file

Proposed Replacement
http://www.mediafire.com/file/i5d8943ruj58yvn/ferrari_2.jpg/file

Any Ideas?

Regards

DJ

 

Not familiar with this issue. Can you have the original rebuilt? Might be a better option.